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| Assoc. Prof. Dr. Sinan Kandemir | Res. Assist. Senagül Tunca Taşkıran | |||
| Prof. Dr. Metin Tanoğlu | ||||
| Assist. Prof. Dr. M. Fatih Toksoy | ||||
Composite Materials Laboratory
Responsible Faculty Member
- Mechanical Engineering Building (147)
- +90 232 750 6747
Composite Research Laboratory
Responsible Faculty Member
- Mechanical Engineering Building (Z36)
- +90 232 750 6704
Material Chracterization Laboratory
Responsible Faculty Member
- Mechanical Engineering Building (150)
- +90 232 750 6750
Metal Processing Laboratory
Responsible Faculty Member
- Mechanical Engineering Building (153)
- +90 232 750 6782
Metallography Laboratory
Responsible Faculty Member
- Mechanical Engineering Building (148)
- +90 232 750 6747
Powder Metallurgy Laboratory
Responsible Faculty Member
- Mechanical Engineering Building (145)
- +90 232 750 6745
2010 |
Sezgin, F E; Tanoglu, M; Egilmez, O O; Donmez, C Mechanical Behavior of Polypropylene-based Honeycomb-Core Composite Sandwich Structures Journal Article JOURNAL OF REINFORCED PLASTICS AND COMPOSITES, 29 (10), pp. 1569-1579, 2010, ISSN: 0731-6844. @article{ISI:000278117500013, title = {Mechanical Behavior of Polypropylene-based Honeycomb-Core Composite Sandwich Structures}, author = {F E Sezgin and M Tanoglu and O O Egilmez and C Donmez}, doi = {10.1177/0731684409341674}, issn = {0731-6844}, year = {2010}, date = {2010-05-01}, journal = {JOURNAL OF REINFORCED PLASTICS AND COMPOSITES}, volume = {29}, number = {10}, pages = {1569-1579}, abstract = {This article presents results from an experimental study, investigating the effects of core thickness on the mechanical properties of composite sandwich structures with polypropylene( PP)-based honeycomb core and glass fiber-reinforced polymer (GFRP) face-sheets fabricated by hand lay-up technique. Epoxy matrix and non-crimp glass fibers were used for the production of GFRP laminates. Flatwise compression (FC), edgewise compression (EC), three-point bending (3PB) and double cantilever beam (DCB) tests were performed to evaluate the mechanical behavior of the composite sandwich structures (CSSs). Based on the FC tests, an increase in the compressive modulus and strength was observed with an increase in the core thickness. For EC tests, peak loads up to crush of the sandwich panel is discussed using core thickness. According to the 3PB tests, a decrease in core shear stress and facesheet bending stress was observed as the core thickness increases.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This article presents results from an experimental study, investigating the effects of core thickness on the mechanical properties of composite sandwich structures with polypropylene( PP)-based honeycomb core and glass fiber-reinforced polymer (GFRP) face-sheets fabricated by hand lay-up technique. Epoxy matrix and non-crimp glass fibers were used for the production of GFRP laminates. Flatwise compression (FC), edgewise compression (EC), three-point bending (3PB) and double cantilever beam (DCB) tests were performed to evaluate the mechanical behavior of the composite sandwich structures (CSSs). Based on the FC tests, an increase in the compressive modulus and strength was observed with an increase in the core thickness. For EC tests, peak loads up to crush of the sandwich panel is discussed using core thickness. According to the 3PB tests, a decrease in core shear stress and facesheet bending stress was observed as the core thickness increases. |
Coskun, Selim; Ovecoglu, Lutfi M; Ozkal, Burak; Tanoglu, Metin Characterization investigations during mechanical alloying and sintering of W-20 vol% SiC composites Journal Article JOURNAL OF ALLOYS AND COMPOUNDS, 492 (1-2), pp. 576-584, 2010, ISSN: 0925-8388. @article{ISI:000276018900125, title = {Characterization investigations during mechanical alloying and sintering of W-20 vol% SiC composites}, author = {Selim Coskun and Lutfi M Ovecoglu and Burak Ozkal and Metin Tanoglu}, doi = {10.1016/j.jallcom.2009.11.185}, issn = {0925-8388}, year = {2010}, date = {2010-03-01}, journal = {JOURNAL OF ALLOYS AND COMPOUNDS}, volume = {492}, number = {1-2}, pages = {576-584}, abstract = {The effect of mechanical alloying and the sintering regime on the microstructural and the physical properties of W-SiC composites were investigated. Powder mixtures of W-20 vol.% SiC were mechanically alloyed (MA'd) using a Spex mill for 3 h, 6 h and 24 h. MA'd powders were characterized by Laser Diffraction Particle Size Analyzer, SEM and XRD investigations. MA'd W-20 vol.% SiC powder composites were sintered under inert Ar and reducing H(2) gas conditions at 1680 degrees C and 1770 degrees C for 1 h. The microstructural and mechanical characterizations of the sintered samples were carried out by scanning electron microscope (SEM) and X-ray diffraction (XRD) and Vickers Hardness analyses. The addition of SiC remarkably increases the hardness of the composites. Hardness is also increased with decreasing grain size and increasing amount of MA. (C) 2009 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The effect of mechanical alloying and the sintering regime on the microstructural and the physical properties of W-SiC composites were investigated. Powder mixtures of W-20 vol.% SiC were mechanically alloyed (MA'd) using a Spex mill for 3 h, 6 h and 24 h. MA'd powders were characterized by Laser Diffraction Particle Size Analyzer, SEM and XRD investigations. MA'd W-20 vol.% SiC powder composites were sintered under inert Ar and reducing H(2) gas conditions at 1680 degrees C and 1770 degrees C for 1 h. The microstructural and mechanical characterizations of the sintered samples were carried out by scanning electron microscope (SEM) and X-ray diffraction (XRD) and Vickers Hardness analyses. The addition of SiC remarkably increases the hardness of the composites. Hardness is also increased with decreasing grain size and increasing amount of MA. (C) 2009 Elsevier B.V. All rights reserved. |
2009 |
Balikoglu, Fatih; Akkurt, Sedat Isothermal corrosion testing of frit furnace refractories Journal Article CERAMICS INTERNATIONAL, 35 (8), pp. 3411-3419, 2009, ISSN: 0272-8842. @article{ISI:000271368100062, title = {Isothermal corrosion testing of frit furnace refractories}, author = {Fatih Balikoglu and Sedat Akkurt}, doi = {10.1016/j.ceramint.2009.06.002}, issn = {0272-8842}, year = {2009}, date = {2009-12-01}, journal = {CERAMICS INTERNATIONAL}, volume = {35}, number = {8}, pages = {3411-3419}, abstract = {In this paper, the corrosion behaviour of aluminosilicate type refractories in frit melts is studied in an isothermal corrosion test setup. A refractory brick of largely andalusite and sillimanite composition was compared to another refractory brick of mullite and sillimanite composition, both of which were made by different manufacturers for use in different frit furnaces. The industrial frit used for corrosion tests was a commercial product used in a wall tile glaze formulation. Corrosion tests conducted under isothermal conditions provide quantitative and reproducible data about the corrosion performance of refractories. In this study, tests were performed by partially immersing a 15 mm x 15 mm x 115 mm refractory specimen into a frit melt at temperatures between 1404 and 1504 degrees C. The effects of temperature, duration of exposure and the refractory brick type were investigated using a statistically designed set of experiments. The ANOVA (analysis of variance) table indicated that temperature and test duration were the most important factor effects, as expected. Increasing both temperature and exposure duration led to an increased amount of corrosion as measured by the cross-sectional area loss of the corroded refractory specimen. Postmortem microstructural analysis was also done on the specimens, with extensive amount of ZnO center dot Al2O3 precipitation observed along the frit-refractory interface, where crystals of mullite and alumina were also found to precipitate. Increasing the amount of exposure time and temperature produced more ZnO center dot Al2O3 precipitation. As identified by SEM-EDS analysis, mullite crystals were in the needle-like morphology, while alumina crystals were generally cubic. Additional experiments were conducted by rotating the specimens in the melt at 50 rpm of rotational speed. Due to the reduction of boundary layer thickness, more dissolution was observed from the rotated specimens. In all specimens, corrosion was more pronounced in the bond phase than through the large filler grains of mullite and andalusite. (c) 2009 Elsevier Ltd and Techna Group S.r.l. All fights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, the corrosion behaviour of aluminosilicate type refractories in frit melts is studied in an isothermal corrosion test setup. A refractory brick of largely andalusite and sillimanite composition was compared to another refractory brick of mullite and sillimanite composition, both of which were made by different manufacturers for use in different frit furnaces. The industrial frit used for corrosion tests was a commercial product used in a wall tile glaze formulation. Corrosion tests conducted under isothermal conditions provide quantitative and reproducible data about the corrosion performance of refractories. In this study, tests were performed by partially immersing a 15 mm x 15 mm x 115 mm refractory specimen into a frit melt at temperatures between 1404 and 1504 degrees C. The effects of temperature, duration of exposure and the refractory brick type were investigated using a statistically designed set of experiments. The ANOVA (analysis of variance) table indicated that temperature and test duration were the most important factor effects, as expected. Increasing both temperature and exposure duration led to an increased amount of corrosion as measured by the cross-sectional area loss of the corroded refractory specimen. Postmortem microstructural analysis was also done on the specimens, with extensive amount of ZnO center dot Al2O3 precipitation observed along the frit-refractory interface, where crystals of mullite and alumina were also found to precipitate. Increasing the amount of exposure time and temperature produced more ZnO center dot Al2O3 precipitation. As identified by SEM-EDS analysis, mullite crystals were in the needle-like morphology, while alumina crystals were generally cubic. Additional experiments were conducted by rotating the specimens in the melt at 50 rpm of rotational speed. Due to the reduction of boundary layer thickness, more dissolution was observed from the rotated specimens. In all specimens, corrosion was more pronounced in the bond phase than through the large filler grains of mullite and andalusite. (c) 2009 Elsevier Ltd and Techna Group S.r.l. All fights reserved. |
Seyhan, A T; Sun, Z; Deitzel, J; Tanoglu, M; Heider, D Cure kinetics of vapor grown carbon nanofiber (VGCNF) modified epoxy resin suspensions and fracture toughness of their resulting nanocomposites Journal Article MATERIALS CHEMISTRY AND PHYSICS, 118 (1), pp. 234-242, 2009, ISSN: 0254-0584. @article{ISI:000271556000042, title = {Cure kinetics of vapor grown carbon nanofiber (VGCNF) modified epoxy resin suspensions and fracture toughness of their resulting nanocomposites}, author = {A T Seyhan and Z Sun and J Deitzel and M Tanoglu and D Heider}, doi = {10.1016/j.matchemphys.2009.07.045}, issn = {0254-0584}, year = {2009}, date = {2009-11-01}, journal = {MATERIALS CHEMISTRY AND PHYSICS}, volume = {118}, number = {1}, pages = {234-242}, abstract = {In this study, the cure kinetics of Cycom 977-20. an aerospace grade toughened epoxy resin, and its suspensions containing various amounts (1, 3 and 5 wt.%) of vapor grown carbon nanofibers (VGCNFs) with and without chemical treatment were monitored via dynamic and isothermal dynamic scanning calorimetry (DSC) measurements. For this purpose, VGCNFs were first oxidized in nitric acid and then functionalized with 3-glycidoxypropyltrimethoxy silane (GPTMS) coupling agent. Fourier transform infrared (FTIR) spectroscopy was subsequently used to verify the chemical functional groups grafted onto the surfaces of VGCNFs. Sonication technique was conducted to facilitate proper dispersion of as-received, acid treated and silanized VGCNFs within epoxy resin. Dynamic DSC measurements showed that silanized VGCNF modified resin suspensions exhibited higher heat of cure compared to those with as-received VGCNFs. Experimentally obtained isothermal DSC data was then con elated with Kamal phenomenological model. Based on the model predictions, it was found that silanized VGCNFs; maximized the cure reaction rates at the very initial stage of the reaction. Accordingly, an optimized curing cycle was applied to harden resin suspensions. Fracture testing was then carried out on the cured samples in order to relate the curing behavior of VGCNF modified resin suspensions to mechanical response of their resulting nanocomposites With addition of 1 wt % of silanized VGCNFs, the fracture toughness value of neat epoxy was found to be improved by 12%. SEM was further employed to examine the fracture surfaces of the samples. (C) 2009 Elsevier B V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, the cure kinetics of Cycom 977-20. an aerospace grade toughened epoxy resin, and its suspensions containing various amounts (1, 3 and 5 wt.%) of vapor grown carbon nanofibers (VGCNFs) with and without chemical treatment were monitored via dynamic and isothermal dynamic scanning calorimetry (DSC) measurements. For this purpose, VGCNFs were first oxidized in nitric acid and then functionalized with 3-glycidoxypropyltrimethoxy silane (GPTMS) coupling agent. Fourier transform infrared (FTIR) spectroscopy was subsequently used to verify the chemical functional groups grafted onto the surfaces of VGCNFs. Sonication technique was conducted to facilitate proper dispersion of as-received, acid treated and silanized VGCNFs within epoxy resin. Dynamic DSC measurements showed that silanized VGCNF modified resin suspensions exhibited higher heat of cure compared to those with as-received VGCNFs. Experimentally obtained isothermal DSC data was then con elated with Kamal phenomenological model. Based on the model predictions, it was found that silanized VGCNFs; maximized the cure reaction rates at the very initial stage of the reaction. Accordingly, an optimized curing cycle was applied to harden resin suspensions. Fracture testing was then carried out on the cured samples in order to relate the curing behavior of VGCNF modified resin suspensions to mechanical response of their resulting nanocomposites With addition of 1 wt % of silanized VGCNFs, the fracture toughness value of neat epoxy was found to be improved by 12%. SEM was further employed to examine the fracture surfaces of the samples. (C) 2009 Elsevier B V. All rights reserved. |
Seyhan, Tugrul A; Tanoglu, Metin; Schulte, Karl MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 523 (1-2), pp. 85-92, 2009, ISSN: 0921-5093. @article{ISI:000270632900014, title = {Tensile mechanical behavior and fracture toughness of MWCNT and DWCNT modified vinyl-ester/polyester hybrid nanocomposites produced by 3-roll milling}, author = {Tugrul A Seyhan and Metin Tanoglu and Karl Schulte}, doi = {10.1016/j.msea.2009.05.035}, issn = {0921-5093}, year = {2009}, date = {2009-10-01}, journal = {MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, volume = {523}, number = {1-2}, pages = {85-92}, abstract = {This study aims to investigate the tensile mechanical behavior and fracture toughness of vinyl-ester/polyester hybrid nanocomposites containing various types of nanofillers, including multi- and double-walled carbon nanotubes with and without amine functional groups (MWCNTs, DWCNTs, MWCNT-NH2 and DWCNT-NH2). To prepare the resin suspensions, very low contents (0.05, 0.1 and 0.3 wt.%) of carbon nanotubes (CNTs) were dispersed within a specially synthesized styrene-free polyester resin, conducting 3-roll milling technique. The collected resin stuff was subsequently blended with vinyl-ester via mechanical stirring to achieve final suspensions prior to polymerization. Nanocomposites containing MWCNTs and MWCNT-NH2 were found to exhibit higher tensile strength and modulus as well as larger fracture toughness and fracture energy compared to neat hybrid polymer. However, incorporation of similar contents of DWCNTs and DWCNT-NH2 into the hybrid resin did not reflect the same improvement in the corresponding mechanical properties. Furthermore, experimentally measured elastic moduli of the nanocomposites containing DWCNTs, DWCNT-NH2, MWCNTs and MWCNT-NH2 were fitted to Halphin-Tsai model. Regardless of amine functional groups or content of carbon nanotubes, MWCNT modified nanocomposites exhibited better agreement between the predicted and the measured elastic moduli values compared to nanocomposites with DWCNTs. Furthermore, Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to reveal dispersion state of the carbon nanotubes within the hybrid polymer and to examine the CNT induced failure modes that occurred under mechanical loading, respectively. Based on the experimental findings obtained, it was emphasized that the types of CNTs and presence of amine functional groups on the surface of CNTs affects substantially the chemical interactions at the interface, thus tuning the ultimate mechanical performance of the resulting nanocomposites. (C) 2009 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study aims to investigate the tensile mechanical behavior and fracture toughness of vinyl-ester/polyester hybrid nanocomposites containing various types of nanofillers, including multi- and double-walled carbon nanotubes with and without amine functional groups (MWCNTs, DWCNTs, MWCNT-NH2 and DWCNT-NH2). To prepare the resin suspensions, very low contents (0.05, 0.1 and 0.3 wt.%) of carbon nanotubes (CNTs) were dispersed within a specially synthesized styrene-free polyester resin, conducting 3-roll milling technique. The collected resin stuff was subsequently blended with vinyl-ester via mechanical stirring to achieve final suspensions prior to polymerization. Nanocomposites containing MWCNTs and MWCNT-NH2 were found to exhibit higher tensile strength and modulus as well as larger fracture toughness and fracture energy compared to neat hybrid polymer. However, incorporation of similar contents of DWCNTs and DWCNT-NH2 into the hybrid resin did not reflect the same improvement in the corresponding mechanical properties. Furthermore, experimentally measured elastic moduli of the nanocomposites containing DWCNTs, DWCNT-NH2, MWCNTs and MWCNT-NH2 were fitted to Halphin-Tsai model. Regardless of amine functional groups or content of carbon nanotubes, MWCNT modified nanocomposites exhibited better agreement between the predicted and the measured elastic moduli values compared to nanocomposites with DWCNTs. Furthermore, Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to reveal dispersion state of the carbon nanotubes within the hybrid polymer and to examine the CNT induced failure modes that occurred under mechanical loading, respectively. Based on the experimental findings obtained, it was emphasized that the types of CNTs and presence of amine functional groups on the surface of CNTs affects substantially the chemical interactions at the interface, thus tuning the ultimate mechanical performance of the resulting nanocomposites. (C) 2009 Elsevier B.V. All rights reserved. |
Sutcu, Mucahit; Akkurt, Sedat; Okur, Salih Influence of crystallographic orientation on hydration of MgO single crystals Journal Article CERAMICS INTERNATIONAL, 35 (7), pp. 2571-2576, 2009, ISSN: 0272-8842. @article{ISI:000268656400004, title = {Influence of crystallographic orientation on hydration of MgO single crystals}, author = {Mucahit Sutcu and Sedat Akkurt and Salih Okur}, doi = {10.1016/j.ceramint.2009.02.012}, issn = {0272-8842}, year = {2009}, date = {2009-09-01}, journal = {CERAMICS INTERNATIONAL}, volume = {35}, number = {7}, pages = {2571-2576}, abstract = {This study has been performed in order to find out the influence of crystallographic orientation on hydration of MgO single crystal substrates with (1 0 0)-, (1 1 0)-, and (1 1 1)-orientations. The samples were left in a hydration chamber with an 88% relative humidity for 18 h at room temperature. The effect of humidity on the samples was examined by scanning probe microscope (SPM) and scanning electron microscope (SEM) which showed that the degree of hydration was noticeably influenced by the crystallographic orientation. It was found that the MgO with (1 1 1)orientation has the highest tendency to hydrate than the other orientations. Second most affected sample was (1 1 0) crystal. Loss of MgO on the surface by hydration is most severe when the crystal is oriented in (1 1 1) plane with the maximum hydrate layer thickness of 174 nm after 18 h of exposure. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study has been performed in order to find out the influence of crystallographic orientation on hydration of MgO single crystal substrates with (1 0 0)-, (1 1 0)-, and (1 1 1)-orientations. The samples were left in a hydration chamber with an 88% relative humidity for 18 h at room temperature. The effect of humidity on the samples was examined by scanning probe microscope (SPM) and scanning electron microscope (SEM) which showed that the degree of hydration was noticeably influenced by the crystallographic orientation. It was found that the MgO with (1 1 1)orientation has the highest tendency to hydrate than the other orientations. Second most affected sample was (1 1 0) crystal. Loss of MgO on the surface by hydration is most severe when the crystal is oriented in (1 1 1) plane with the maximum hydrate layer thickness of 174 nm after 18 h of exposure. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved. |
Sutcu, Mucahit; Akkurt, Sedat The use of recycled paper processing residues in making porous brick with reduced thermal conductivity Journal Article CERAMICS INTERNATIONAL, 35 (7), pp. 2625-2631, 2009, ISSN: 0272-8842. @article{ISI:000268656400010, title = {The use of recycled paper processing residues in making porous brick with reduced thermal conductivity}, author = {Mucahit Sutcu and Sedat Akkurt}, doi = {10.1016/j.ceramint.2009.02.027}, issn = {0272-8842}, year = {2009}, date = {2009-09-01}, journal = {CERAMICS INTERNATIONAL}, volume = {35}, number = {7}, pages = {2625-2631}, abstract = {Production of porous and light-weight bricks with reduced thermal conductivity and acceptable compressive strength is accomplished. Paper processing residues were used as an additive to an earthenware brick to produce the pores. SEM-EDS, XRD, XRF and TG-DTA analysis of the paper waste and brick raw material were performed. Mixtures containing brick raw materials and the paper waste were prepared at different proportions (up to 30 wt%). The granulated powder mixtures were compressed in a hydraulic press, and the green bodies were dried before firing at 1100 degrees C. Dilatometric behaviours, drying and firing shrinkages were investigated as well as the loss on ignition, bulk density, apparent porosity, water absorption and thermal conductivity values of the fired samples. Their mechanical and microstructural properties were also investigated. The results obtained showed that the use of paper processing residues decreased the fired density of the bricks down to 1.28 g/cm(3). Compressive strengths of the brick samples produced in this study were higher than that required by the standards. Thermal conductivity of the porous brick produced in this study (<0.4 W/m K) showed more than 50% reduction compared to local brick of the same composition (0.8 W/m K). Conversion of this product to a perforated brick may reduce its thermal conductivity to very low values. Successful preliminary tests were conducted on an industrial scale. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Production of porous and light-weight bricks with reduced thermal conductivity and acceptable compressive strength is accomplished. Paper processing residues were used as an additive to an earthenware brick to produce the pores. SEM-EDS, XRD, XRF and TG-DTA analysis of the paper waste and brick raw material were performed. Mixtures containing brick raw materials and the paper waste were prepared at different proportions (up to 30 wt%). The granulated powder mixtures were compressed in a hydraulic press, and the green bodies were dried before firing at 1100 degrees C. Dilatometric behaviours, drying and firing shrinkages were investigated as well as the loss on ignition, bulk density, apparent porosity, water absorption and thermal conductivity values of the fired samples. Their mechanical and microstructural properties were also investigated. The results obtained showed that the use of paper processing residues decreased the fired density of the bricks down to 1.28 g/cm(3). Compressive strengths of the brick samples produced in this study were higher than that required by the standards. Thermal conductivity of the porous brick produced in this study (<0.4 W/m K) showed more than 50% reduction compared to local brick of the same composition (0.8 W/m K). Conversion of this product to a perforated brick may reduce its thermal conductivity to very low values. Successful preliminary tests were conducted on an industrial scale. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved. |
2008 |
Erdogan, B C; Seyhan, A T; Ocak, Y; Tanoglu, M; Balkose, D; Ulku, S Cure kinetics of epoxy resin-natural zeolite composites Journal Article JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, 94 (3), pp. 743-747, 2008, ISSN: 1388-6150, (31st International Conference on Vacuum Microbalance Techniques, Izmir Inst Technol, Izmir, TURKEY, SEP 12-14, 2007). @article{ISI:000261832000025, title = {Cure kinetics of epoxy resin-natural zeolite composites}, author = {B C Erdogan and A T Seyhan and Y Ocak and M Tanoglu and D Balkose and S Ulku}, doi = {10.1007/s10973-008-9366-7}, issn = {1388-6150}, year = {2008}, date = {2008-12-01}, journal = {JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY}, volume = {94}, number = {3}, pages = {743-747}, organization = {Izmir Inst Technol, Engn Fac, Dept Chem Engn; Turkish Sci & Technol Res Council; Ege Branch Chamber Chem Engineers; Ege Reg Chamber Ind; Bausparkasse Mainz; Rubothem; Pigment A; Terra Lab; Terra A; IItek Ltd}, abstract = {The cure kinetics of epoxy resin and epoxy resin containing 10 mass% of natural zeolite were investigated using differential scanning calorimetry (DSC). The conformity of the cure kinetic data of epoxy and epoxy-zeolite system was checked with the auto-catalytic cure rate model. The results indicated that the hydroxyl group on the zeolite surface played a significant role in the autocatalytic reaction mechanism. This group was able to form a new transition state between anhydride hardener and epoxide group. The natural zeolite particles acted as catalyst for the epoxy system by promoting its curing rate.}, note = {31st International Conference on Vacuum Microbalance Techniques, Izmir Inst Technol, Izmir, TURKEY, SEP 12-14, 2007}, keywords = {}, pubstate = {published}, tppubtype = {article} } The cure kinetics of epoxy resin and epoxy resin containing 10 mass% of natural zeolite were investigated using differential scanning calorimetry (DSC). The conformity of the cure kinetic data of epoxy and epoxy-zeolite system was checked with the auto-catalytic cure rate model. The results indicated that the hydroxyl group on the zeolite surface played a significant role in the autocatalytic reaction mechanism. This group was able to form a new transition state between anhydride hardener and epoxide group. The natural zeolite particles acted as catalyst for the epoxy system by promoting its curing rate. |
Seyhan, Tugrul A; Tanoglu, Metin; Schulte, Karl Mode I and mode II fracture toughness of E-glass non-crimp fabric/carbon nanotube (CNT) modified polymer based composites Journal Article ENGINEERING FRACTURE MECHANICS, 75 (18), pp. 5151-5162, 2008, ISSN: 0013-7944. @article{ISI:000261562000013, title = {Mode I and mode II fracture toughness of E-glass non-crimp fabric/carbon nanotube (CNT) modified polymer based composites}, author = {Tugrul A Seyhan and Metin Tanoglu and Karl Schulte}, doi = {10.1016/j.engfracmech.2008.08.003}, issn = {0013-7944}, year = {2008}, date = {2008-12-01}, journal = {ENGINEERING FRACTURE MECHANICS}, volume = {75}, number = {18}, pages = {5151-5162}, abstract = {In this study, mode I and mode II interlaminar fracture toughness, and interlaminar shear strength of E-glass non-crimp fabric/carbon nanotube modified polymer matrix composites were investigated. The matrix resin containing 0.1 wt.% of amino functionalized multi walled carbon nanotubes were prepared, utilizing the 3-roll milling technique. Composite laminates were manufactured via vacuum assisted resin transfer molding process. Carbon nanotube modified laminates were found to exhibit 8% and 11% higher mode 11 interlaminar fracture toughness and interlaminar shear strength values, respectively, as compared to the base laminates. However, no significant improvement was observed for mode I interlaminar fracture toughness values. Furthermore, Optical microscopy and scanning electron microscopy were utilized to monitor the distribution of carbon nanotubes within the composite microstructure and to examine the fracture surfaces of the failed specimens, respectively. (c) 2008 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, mode I and mode II interlaminar fracture toughness, and interlaminar shear strength of E-glass non-crimp fabric/carbon nanotube modified polymer matrix composites were investigated. The matrix resin containing 0.1 wt.% of amino functionalized multi walled carbon nanotubes were prepared, utilizing the 3-roll milling technique. Composite laminates were manufactured via vacuum assisted resin transfer molding process. Carbon nanotube modified laminates were found to exhibit 8% and 11% higher mode 11 interlaminar fracture toughness and interlaminar shear strength values, respectively, as compared to the base laminates. However, no significant improvement was observed for mode I interlaminar fracture toughness values. Furthermore, Optical microscopy and scanning electron microscopy were utilized to monitor the distribution of carbon nanotubes within the composite microstructure and to examine the fracture surfaces of the failed specimens, respectively. (c) 2008 Elsevier Ltd. All rights reserved. |
Rahimov, R N; Khalilova, A A; Arasly, D H; Aliyev, M I; Tanoglu, M; Ozyuzer, L Thermostable tensoresistors of Co doped GaSb-FeGa1.3 eutectic composites Journal Article SENSORS AND ACTUATORS A-PHYSICAL, 147 (2), pp. 436-440, 2008, ISSN: 0924-4247. @article{ISI:000259685600013, title = {Thermostable tensoresistors of Co doped GaSb-FeGa1.3 eutectic composites}, author = {R N Rahimov and A A Khalilova and D H Arasly and M I Aliyev and M Tanoglu and L Ozyuzer}, doi = {10.1016/j.sna.2008.05.032}, issn = {0924-4247}, year = {2008}, date = {2008-10-01}, journal = {SENSORS AND ACTUATORS A-PHYSICAL}, volume = {147}, number = {2}, pages = {436-440}, abstract = {The microstructure and tensoresistive properties of GaSb-FeCa1.3 eutectic composites doped with 0.1% Co have been investigated. It was found that the Co impurity atoms mainly accumulate in the metallic inclusions. The length of the inclusions in GaSb-FeGa1.3(Co) was measured to be about half of those in uncloped GaSb-FeGa1.3 eutectics. The tensometric characteristics of gauges based on GaSb-FeGa1.3(Co) have been found to be more thermostable than uncloped samples. (C) 2008 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The microstructure and tensoresistive properties of GaSb-FeCa1.3 eutectic composites doped with 0.1% Co have been investigated. It was found that the Co impurity atoms mainly accumulate in the metallic inclusions. The length of the inclusions in GaSb-FeGa1.3(Co) was measured to be about half of those in uncloped GaSb-FeGa1.3 eutectics. The tensometric characteristics of gauges based on GaSb-FeGa1.3(Co) have been found to be more thermostable than uncloped samples. (C) 2008 Elsevier B.V. All rights reserved. |
Kavalci, Sedat; Yalamac, Emre; Akkurt, Sedat Effects of boron addition and intensive grinding on synthesis of anorthite ceramics Journal Article CERAMICS INTERNATIONAL, 34 (7), pp. 1629-1635, 2008, ISSN: 0272-8842. @article{ISI:000259133300009, title = {Effects of boron addition and intensive grinding on synthesis of anorthite ceramics}, author = {Sedat Kavalci and Emre Yalamac and Sedat Akkurt}, doi = {10.1016/j.ceramint.2007.07.007}, issn = {0272-8842}, year = {2008}, date = {2008-09-01}, journal = {CERAMICS INTERNATIONAL}, volume = {34}, number = {7}, pages = {1629-1635}, abstract = {Anorthite ceramics were synthesized starting from mixtures prepared by using mechanochemical methods with boron oxide addition. The raw materials used in this study were Sivas Kaolin, calcined alumina/Al(OH)(3) and calcite. Statistical experimental design techniques (SED) were used in order to determine and analyze the more important process variables for synthesizing anorthite ceramics. Phase characterizations of synthesized 14 powders were performed by XRD using Cu K alpha radiation. Microstructural characterization was performed by SEM. The results of screening experimental design clarified that the temperature was the most important process variable. Second most important process variable was grinding speed of starting mixture which was followed by additive amount and additive type. The effect of both additive use and grinding on anorthite synthesis helped decrease the synthesis temperature down to 900 degrees C. (C) 2007 Elsevier Ltd and Techna Group S.r.l. All fights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Anorthite ceramics were synthesized starting from mixtures prepared by using mechanochemical methods with boron oxide addition. The raw materials used in this study were Sivas Kaolin, calcined alumina/Al(OH)(3) and calcite. Statistical experimental design techniques (SED) were used in order to determine and analyze the more important process variables for synthesizing anorthite ceramics. Phase characterizations of synthesized 14 powders were performed by XRD using Cu K alpha radiation. Microstructural characterization was performed by SEM. The results of screening experimental design clarified that the temperature was the most important process variable. Second most important process variable was grinding speed of starting mixture which was followed by additive amount and additive type. The effect of both additive use and grinding on anorthite synthesis helped decrease the synthesis temperature down to 900 degrees C. (C) 2007 Elsevier Ltd and Techna Group S.r.l. All fights reserved. |
Kaya, Elcin; Tanoglu, Metin; Okur, Salih Layered clay/epoxy nanocomposites: Thermomechanical, flame retardancy, and optical properties Journal Article JOURNAL OF APPLIED POLYMER SCIENCE, 109 (2), pp. 834-840, 2008, ISSN: 0021-8995. @article{ISI:000256267200020, title = {Layered clay/epoxy nanocomposites: Thermomechanical, flame retardancy, and optical properties}, author = {Elcin Kaya and Metin Tanoglu and Salih Okur}, doi = {10.1002/app.28168}, issn = {0021-8995}, year = {2008}, date = {2008-07-01}, journal = {JOURNAL OF APPLIED POLYMER SCIENCE}, volume = {109}, number = {2}, pages = {834-840}, abstract = {In this study, layered clay/polymer nanocomposites were developed based on epoxy resins and montmorillonite as the nanoplatelet reinforcement. Clay particles were treated with hexadecyltrimethylammonium chloride (HTCA) through an ion exchange reaction. In this way, Na+ interlayer cations of the clay is exchanged with onium cation of the surfactant that turns the hydrophilic clays (MMT) to organophilic (OMMT) characteristics. Thermal analysis results revealed that the glass transition temperature (T-g) and the dynamic mechanical properties including the storage and loss modulus of the neat epoxy resin increases by the incorporation of clay particles. It was also found that flame resistance of the polymer is improved by the addition of the clay particles. (C) 2008 Wiley Periodicals, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, layered clay/polymer nanocomposites were developed based on epoxy resins and montmorillonite as the nanoplatelet reinforcement. Clay particles were treated with hexadecyltrimethylammonium chloride (HTCA) through an ion exchange reaction. In this way, Na+ interlayer cations of the clay is exchanged with onium cation of the surfactant that turns the hydrophilic clays (MMT) to organophilic (OMMT) characteristics. Thermal analysis results revealed that the glass transition temperature (T-g) and the dynamic mechanical properties including the storage and loss modulus of the neat epoxy resin increases by the incorporation of clay particles. It was also found that flame resistance of the polymer is improved by the addition of the clay particles. (C) 2008 Wiley Periodicals, Inc. |
Alpöz, Riza A; Ertuḡrul, Fahinur; Cogulu, Dilsah; Ak, Asli Topaloḡlu; Tanoḡlu, Metin; ç, El Effects of light curing method and exposure time on mechanical properties of resin based dental materials Journal Article European journal of dentistry, 2 , pp. 37, 2008. @article{alpoz2008effects, title = {Effects of light curing method and exposure time on mechanical properties of resin based dental materials}, author = {Riza A Alpöz and Fahinur Ertuḡrul and Dilsah Cogulu and Asli Topaloḡlu Ak and Metin Tanoḡlu and El{ç}in Kaya}, year = {2008}, date = {2008-01-01}, journal = {European journal of dentistry}, volume = {2}, pages = {37}, publisher = {Dental Investigations Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2007 |
Guden, M; Yueksel, S; Tasdemirci, A; Tanoglu, M COMPOSITE STRUCTURES, 81 (4), pp. 480-490, 2007, ISSN: 0263-8223. @article{ISI:000249256200002, title = {Effect of aluminum closed-cell foam filling on the quasi-static axial crush performance of glass fiber reinforced polyester composite and aluminum/composite hybrid tubes}, author = {M Guden and S Yueksel and A Tasdemirci and M Tanoglu}, doi = {10.1016/j.compstruct.2006.09.005}, issn = {0263-8223}, year = {2007}, date = {2007-12-01}, journal = {COMPOSITE STRUCTURES}, volume = {81}, number = {4}, pages = {480-490}, abstract = {The effect of Al closed-cell foam filling on the quasi-static crushing behavior of an E-glass woven fabric polyester composite tube and thin-walled Al/polyester composite hybrid tube was experimentally investigated. For comparison, empty Al, empty composite and empty hybrid tubes were also tested. Empty composite and empty hybrid tubes crushed predominantly in progressive crushing mode, without applying any triggering mechanism. Foam filling was found to be ineffective in increasing the crushing loads of the composite tubes over the sum of the crushing loads of empty composite tube and foam. However, foam filling stabilized the composite progressive crushing mode. In empty hybrid tubes, the deformation mode of the inner Al tube was found to be a more complex form of the diamond mode of deformation of empty Al tube, leading to higher crushing load values than the sum of the crushing load values of empty composite tube and empty metal tube. The foam filling of hybrid tubes however resulted in axial splitting of the outer composite tube due to the resistance imposed by the foam filler to Al tube inward folding and hence it was ineffective in increasing crushing load and SAE values over those of empty hybrid tubes. (C) 2006 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The effect of Al closed-cell foam filling on the quasi-static crushing behavior of an E-glass woven fabric polyester composite tube and thin-walled Al/polyester composite hybrid tube was experimentally investigated. For comparison, empty Al, empty composite and empty hybrid tubes were also tested. Empty composite and empty hybrid tubes crushed predominantly in progressive crushing mode, without applying any triggering mechanism. Foam filling was found to be ineffective in increasing the crushing loads of the composite tubes over the sum of the crushing loads of empty composite tube and foam. However, foam filling stabilized the composite progressive crushing mode. In empty hybrid tubes, the deformation mode of the inner Al tube was found to be a more complex form of the diamond mode of deformation of empty Al tube, leading to higher crushing load values than the sum of the crushing load values of empty composite tube and empty metal tube. The foam filling of hybrid tubes however resulted in axial splitting of the outer composite tube due to the resistance imposed by the foam filler to Al tube inward folding and hence it was ineffective in increasing crushing load and SAE values over those of empty hybrid tubes. (C) 2006 Elsevier Ltd. All rights reserved. |
Bozkurt, Emrah; Kaya, Elcin; Tanoglu, Metin Mechanical and thermal behavior of non-crimp glass fiber reinforced layered clay/epoxy nanocomposites Journal Article COMPOSITES SCIENCE AND TECHNOLOGY, 67 (15-16), pp. 3394-3403, 2007, ISSN: 0266-3538. @article{ISI:000250910600040, title = {Mechanical and thermal behavior of non-crimp glass fiber reinforced layered clay/epoxy nanocomposites}, author = {Emrah Bozkurt and Elcin Kaya and Metin Tanoglu}, doi = {10.1016/j.compscitech.2007.03.021}, issn = {0266-3538}, year = {2007}, date = {2007-12-01}, journal = {COMPOSITES SCIENCE AND TECHNOLOGY}, volume = {67}, number = {15-16}, pages = {3394-3403}, abstract = {Mechanical and thermal properties of non-crimp glass fiber reinforced clay/epoxy nanocomposites were investigated. Clay/epoxy natiocomposite systems were prepared to use as the matrix material for composite laminates. X-ray diffraction results obtained from natural and modified clays indicated that intergallery spacing of the layered clay increases with surface treatment. Tensile tests indicated that clay loading has minor effect on the tensile properties. Flexural properties of laminates were improved by clay addition due to the improved interface between glass fibers and epoxy. Differential scanning calorimetry (DSC) results showed that the modified clay particles affected the glass transition temperatures (T-g) of the nanocomposites. Incorporation of surface treated clay particles increased the dynamic mechanical properties of nanocomposite laminates. It was found that the flame resistance of composites was improved significantly by clay addition into the epoxy matrix. (C) 2007 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Mechanical and thermal properties of non-crimp glass fiber reinforced clay/epoxy nanocomposites were investigated. Clay/epoxy natiocomposite systems were prepared to use as the matrix material for composite laminates. X-ray diffraction results obtained from natural and modified clays indicated that intergallery spacing of the layered clay increases with surface treatment. Tensile tests indicated that clay loading has minor effect on the tensile properties. Flexural properties of laminates were improved by clay addition due to the improved interface between glass fibers and epoxy. Differential scanning calorimetry (DSC) results showed that the modified clay particles affected the glass transition temperatures (T-g) of the nanocomposites. Incorporation of surface treated clay particles increased the dynamic mechanical properties of nanocomposite laminates. It was found that the flame resistance of composites was improved significantly by clay addition into the epoxy matrix. (C) 2007 Elsevier Ltd. All rights reserved. |
Simsek, Yilmaz; Ozyuzer, Lutfi; Seyhan, Tugrul A; Tanoglu, Metin; Schulte, Karl Temperature dependence of electrical conductivity in double-wall and multi-wall carbon nanotube/polyester nanocomposites Journal Article JOURNAL OF MATERIALS SCIENCE, 42 (23), pp. 9689-9695, 2007, ISSN: 0022-2461. @article{ISI:000249657500026, title = {Temperature dependence of electrical conductivity in double-wall and multi-wall carbon nanotube/polyester nanocomposites}, author = {Yilmaz Simsek and Lutfi Ozyuzer and Tugrul A Seyhan and Metin Tanoglu and Karl Schulte}, doi = {10.1007/s10853-007-1943-9}, issn = {0022-2461}, year = {2007}, date = {2007-12-01}, journal = {JOURNAL OF MATERIALS SCIENCE}, volume = {42}, number = {23}, pages = {9689-9695}, abstract = {The aim of this study is to investigate temperature dependence of electrical conductivity of carbon nanotube (CNT)/polyester nanocomposites from room temperature to 77 K using four-point probe test method. To produce nanocomposites, various types and amounts of CNTs (0.1, 0.3 and 0.5 wt.%) were dispersed via 3-roll mill technique within a specially formulized resin blend of thermoset polyesters. CNTs used in the study include multi walled carbon nanotubes (MWCNT) and double-walled carbon nanotubes (DWCNT) with and without amine functional groups (-NH2). It was observed that the incorporation of carbon nanotubes into resin blend yields electrically percolating networks and electrical conductivity of the resulting nanocomposites increases with increasing amount of nanotubes. However, nanocomposites containing amino functionalized carbon nanotubes exhibit relatively lower electrical conductivity compared to those with non-functionalized carbon nanotubes. To get better interpretation of the mechanism leading to conductive network via CNTs with and without amine functional groups, the experimental results were fitted to fluctuation-induced tunneling through the barriers between the metallic regions model. It was found that the results are in good agreement with prediction of proposed model.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of this study is to investigate temperature dependence of electrical conductivity of carbon nanotube (CNT)/polyester nanocomposites from room temperature to 77 K using four-point probe test method. To produce nanocomposites, various types and amounts of CNTs (0.1, 0.3 and 0.5 wt.%) were dispersed via 3-roll mill technique within a specially formulized resin blend of thermoset polyesters. CNTs used in the study include multi walled carbon nanotubes (MWCNT) and double-walled carbon nanotubes (DWCNT) with and without amine functional groups (-NH2). It was observed that the incorporation of carbon nanotubes into resin blend yields electrically percolating networks and electrical conductivity of the resulting nanocomposites increases with increasing amount of nanotubes. However, nanocomposites containing amino functionalized carbon nanotubes exhibit relatively lower electrical conductivity compared to those with non-functionalized carbon nanotubes. To get better interpretation of the mechanism leading to conductive network via CNTs with and without amine functional groups, the experimental results were fitted to fluctuation-induced tunneling through the barriers between the metallic regions model. It was found that the results are in good agreement with prediction of proposed model. |
Altay, E; Shahwan, T; Tanoglu, M POWDER TECHNOLOGY, 178 (3), pp. 194-202, 2007, ISSN: 0032-5910. @article{ISI:000249773000007, title = {Morphosynthesis of CaCO3 at different reaction temperatures and the effects of PDDA, CTAB, and EDTA on the particle morphology and polymorph stability}, author = {E Altay and T Shahwan and M Tanoglu}, doi = {10.1016/j.powtec.2007.05.004}, issn = {0032-5910}, year = {2007}, date = {2007-09-01}, journal = {POWDER TECHNOLOGY}, volume = {178}, number = {3}, pages = {194-202}, abstract = {Facile precipitation of CaCO3 was performed using aqueous solutions of CaCl2 with Na2CO3 over a wide range of mixing and aging temperatures. The precipitation process was then repeated in the presence of PDDA, CTAB, and EDTA at the mixing temperatures of 30 degrees C, 50 degrees C, 70 degrees C, and 90 degrees C. The presence of these additives was seen to greatly suppress the formation of aragonite. Among these additives, EDTA was the one that showed the most prominent effects on particle morphology of CaCO3. The sequence of pH adjustment appeared to be a critical factor for the additive functionality. (C) 2007 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Facile precipitation of CaCO3 was performed using aqueous solutions of CaCl2 with Na2CO3 over a wide range of mixing and aging temperatures. The precipitation process was then repeated in the presence of PDDA, CTAB, and EDTA at the mixing temperatures of 30 degrees C, 50 degrees C, 70 degrees C, and 90 degrees C. The presence of these additives was seen to greatly suppress the formation of aragonite. Among these additives, EDTA was the one that showed the most prominent effects on particle morphology of CaCO3. The sequence of pH adjustment appeared to be a critical factor for the additive functionality. (C) 2007 Elsevier B.V. All rights reserved. |
Akkurt, Sedat; Romagnoli, Marcella; Sutcu, Mucahit DOE and ANN models for powder mixture packing Journal Article AMERICAN CERAMIC SOCIETY BULLETIN, 86 (7), pp. 9101-U11, 2007, ISSN: 0002-7812. @article{ISI:000253621600032, title = {DOE and ANN models for powder mixture packing}, author = {Sedat Akkurt and Marcella Romagnoli and Mucahit Sutcu}, issn = {0002-7812}, year = {2007}, date = {2007-07-01}, journal = {AMERICAN CERAMIC SOCIETY BULLETIN}, volume = {86}, number = {7}, pages = {9101-U11}, abstract = {Design of experiments (DOE) and artificial neural network (ANN) techniques were used to study packing of fused alumina powders composed of three different sizes of particles. The first is the mixture design technique that produces a polynomial model of the powder-packing system. While, the ANN technique is extensively used to model complex systems in many fields. The methodological approach used is mixture design, which can be used to study the influences of two or more additives. It is a structured and organized method for determining the relationship between the components and the output of that process. The mixture design approach permits optimization of size distribution to obtain a target value of porosity. Sensitivity analysis involves the use of the developed ANN model to predict outputs (porosity) at varying levels of the input factor effects.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Design of experiments (DOE) and artificial neural network (ANN) techniques were used to study packing of fused alumina powders composed of three different sizes of particles. The first is the mixture design technique that produces a polynomial model of the powder-packing system. While, the ANN technique is extensively used to model complex systems in many fields. The methodological approach used is mixture design, which can be used to study the influences of two or more additives. It is a structured and organized method for determining the relationship between the components and the output of that process. The mixture design approach permits optimization of size distribution to obtain a target value of porosity. Sensitivity analysis involves the use of the developed ANN model to predict outputs (porosity) at varying levels of the input factor effects. |
Seyhan, A T; Gojny, F H; Tanoglu, M; Schulte, K Rheological and dynamic-mechanical behavior of carbon nanotube/vinyl ester-polyester suspensions and their nanocomposites Journal Article EUROPEAN POLYMER JOURNAL, 43 (7), pp. 2836-2847, 2007, ISSN: 0014-3057. @article{ISI:000248641400009, title = {Rheological and dynamic-mechanical behavior of carbon nanotube/vinyl ester-polyester suspensions and their nanocomposites}, author = {A T Seyhan and F H Gojny and M Tanoglu and K Schulte}, doi = {10.1016/j.eurpolymj.2007.04.022}, issn = {0014-3057}, year = {2007}, date = {2007-07-01}, journal = {EUROPEAN POLYMER JOURNAL}, volume = {43}, number = {7}, pages = {2836-2847}, abstract = {Rheological properties of vinyl ester polyester resin suspensions containing various amounts (0.05, 0.1 and 0.3 wt.%) of multi walled carbon nanotubes (MWCNT) with and without amine functional groups (-NH2) were investigated by utilization of oscillatory rheometer with parallel plate geometry. Dispersion of corresponding carbon nanotubes within the resin blend was accomplished employing high shear mixing technique (3-roll milling). Based on the dynamic viscoelastic measurements, it was observed that at 0.3 wt.% of CNT loadings, storage modulus (G') values of suspensions containing MWCNTs and MWCNT-NH2 exhibited frequency-independent pseudo solid like behavior especially at lower frequencies. Moreover, the loss modulus (G `') values of the resin suspensions with respect to frequency were observed to increase with an increase in contents of CNTs within the resin blend. In addition, steady shear viscosity measurements implied that at each given loading rate, the resin suspensions demonstrated shear thinning behavior regardless of amine functional groups, while the neat resin blend was almost the Newtonian fluid. Furthermore, dynamic mechanical behavior of the nanocomposites achieved by polymerizing the resin blend suspensions with MWCNTs and MWCNT-NH2 was investigated through dynamic mechanical thermal analyzer (DMTA). It was revealed that storage modulus (E') and the loss modulus (E `') values of the resulting nanocomposites increased with regard to carbon nanotubes incorporated into the resin blend. In addition, at each given loading rate, nanocomposites containing MWCNT-NH2 possessed larger loss and storage modulus values as well as higher glass transition temperatures (T-g) as compared to those with MWCNTs. These findings were attributed to evidences for contribution of amine functional groups to chemical interactions at the interface between CNTs and the resin blend matrix. Transmission electron microscopy (TEM) studies performed on the cured resin samples approved that the dispersion state of carbon nanotubes with and without amine functional groups within the matrix resin blend was adequate. This implies that 3-roll milling process described herein is very appropriate technique for blending of carbon nanotubes with a liquid thermoset resin to manufacture nanocomposites with enhanced final properties. (c) 2007 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Rheological properties of vinyl ester polyester resin suspensions containing various amounts (0.05, 0.1 and 0.3 wt.%) of multi walled carbon nanotubes (MWCNT) with and without amine functional groups (-NH2) were investigated by utilization of oscillatory rheometer with parallel plate geometry. Dispersion of corresponding carbon nanotubes within the resin blend was accomplished employing high shear mixing technique (3-roll milling). Based on the dynamic viscoelastic measurements, it was observed that at 0.3 wt.% of CNT loadings, storage modulus (G') values of suspensions containing MWCNTs and MWCNT-NH2 exhibited frequency-independent pseudo solid like behavior especially at lower frequencies. Moreover, the loss modulus (G `') values of the resin suspensions with respect to frequency were observed to increase with an increase in contents of CNTs within the resin blend. In addition, steady shear viscosity measurements implied that at each given loading rate, the resin suspensions demonstrated shear thinning behavior regardless of amine functional groups, while the neat resin blend was almost the Newtonian fluid. Furthermore, dynamic mechanical behavior of the nanocomposites achieved by polymerizing the resin blend suspensions with MWCNTs and MWCNT-NH2 was investigated through dynamic mechanical thermal analyzer (DMTA). It was revealed that storage modulus (E') and the loss modulus (E `') values of the resulting nanocomposites increased with regard to carbon nanotubes incorporated into the resin blend. In addition, at each given loading rate, nanocomposites containing MWCNT-NH2 possessed larger loss and storage modulus values as well as higher glass transition temperatures (T-g) as compared to those with MWCNTs. These findings were attributed to evidences for contribution of amine functional groups to chemical interactions at the interface between CNTs and the resin blend matrix. Transmission electron microscopy (TEM) studies performed on the cured resin samples approved that the dispersion state of carbon nanotubes with and without amine functional groups within the matrix resin blend was adequate. This implies that 3-roll milling process described herein is very appropriate technique for blending of carbon nanotubes with a liquid thermoset resin to manufacture nanocomposites with enhanced final properties. (c) 2007 Elsevier Ltd. All rights reserved. |
Seyhan, Tugrul A; Gojny, Florian H; Tanoglu, Metin; Schulte, Karl Critical aspects related to processing of carbon nano tube/unsaturated thermoset polyester nanocomposites Journal Article EUROPEAN POLYMER JOURNAL, 43 (2), pp. 374-379, 2007, ISSN: 0014-3057. @article{ISI:000244379900010, title = {Critical aspects related to processing of carbon nano tube/unsaturated thermoset polyester nanocomposites}, author = {Tugrul A Seyhan and Florian H Gojny and Metin Tanoglu and Karl Schulte}, doi = {10.1016/j.eurpolymj.2006.11.018}, issn = {0014-3057}, year = {2007}, date = {2007-02-01}, journal = {EUROPEAN POLYMER JOURNAL}, volume = {43}, number = {2}, pages = {374-379}, abstract = {Carbon nanotubes (CNTs) have outstanding mechanical, thermal and electrical properties. As a result, particular interest has been recently given in exploiting these properties by incorporating carbon nanotubes into some form of matrix. Although unsaturated polyesters with styrene have widespread use in the industrial applications, surprisingly there is no study in the literature about CNT/thermoset polyester nanocomposite systems. In the present paper, we underline some important issues and limitations during the processing of unsaturated polyester resins with different types of carbon nanotubes. In that manner, 3-roll mill and sonication techniques were comparatively evaluated to process nanocomposites made of CNTs with and without amine (NH2) functional groups and polyesters. It was found that styrene evaporation from the polyester resin system was a critical issue for nanocomposite processing. Rheological behaviour of the suspensions containing CNTs and tensile strengths of their resulting nanocomposites were characterized. CNT/polyester suspensions exhibited a shear thinning behaviour, while polyester resin blends act as a Newtonian fluid. It was also found that nanotubes with amine functional groups have better tensile strength, as compared to those with untreated CNTs. Transmission electron microscopy (TEM) was also employed to reveal the degree of dispersion of CNTs in the matrix. (c) 2006 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Carbon nanotubes (CNTs) have outstanding mechanical, thermal and electrical properties. As a result, particular interest has been recently given in exploiting these properties by incorporating carbon nanotubes into some form of matrix. Although unsaturated polyesters with styrene have widespread use in the industrial applications, surprisingly there is no study in the literature about CNT/thermoset polyester nanocomposite systems. In the present paper, we underline some important issues and limitations during the processing of unsaturated polyester resins with different types of carbon nanotubes. In that manner, 3-roll mill and sonication techniques were comparatively evaluated to process nanocomposites made of CNTs with and without amine (NH2) functional groups and polyesters. It was found that styrene evaporation from the polyester resin system was a critical issue for nanocomposite processing. Rheological behaviour of the suspensions containing CNTs and tensile strengths of their resulting nanocomposites were characterized. CNT/polyester suspensions exhibited a shear thinning behaviour, while polyester resin blends act as a Newtonian fluid. It was also found that nanotubes with amine functional groups have better tensile strength, as compared to those with untreated CNTs. Transmission electron microscopy (TEM) was also employed to reveal the degree of dispersion of CNTs in the matrix. (c) 2006 Elsevier Ltd. All rights reserved. |
Sutcu, Mucahit; Akkurt, Sedat ANN model for prediction of powder packing Journal Article JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 27 (2-3), pp. 641-644, 2007, ISSN: 0955-2219, (9th Conference and Exhibition of the European-Ceramic-Society, Portoroz, SLOVENIA, JUN 19-23, 2005). @article{ISI:000243265100037, title = {ANN model for prediction of powder packing}, author = {Mucahit Sutcu and Sedat Akkurt}, doi = {10.1016/j.jeurceramsoc.2006.04.044}, issn = {0955-2219}, year = {2007}, date = {2007-01-01}, journal = {JOURNAL OF THE EUROPEAN CERAMIC SOCIETY}, volume = {27}, number = {2-3}, pages = {641-644}, organization = {European Ceram Soc}, abstract = {A multilayer feed forward backpropagation (MFFB) learning algorithm was used as an artificial neural network (ANN) tool to predict packing of fused alumina powder mixtures of three different sizes in green state. The data used in model construction were collected by mixing and pressing powders with average particle sizes of 350, 30 and 3 mu m and with narrow particle size distributions. The data sets that were composed of green densities of cylindrical pellets were first randomly partitioned into two for training and testing of the ANN models. Based on the training data an ANN model of the packing efficiencies was created with low average error levels (3.36%). Testing of the model was also performed with successfully good average error levels of 3.39%. (c) 2006 Elsevier Ltd. All fights reserved.}, note = {9th Conference and Exhibition of the European-Ceramic-Society, Portoroz, SLOVENIA, JUN 19-23, 2005}, keywords = {}, pubstate = {published}, tppubtype = {article} } A multilayer feed forward backpropagation (MFFB) learning algorithm was used as an artificial neural network (ANN) tool to predict packing of fused alumina powder mixtures of three different sizes in green state. The data used in model construction were collected by mixing and pressing powders with average particle sizes of 350, 30 and 3 mu m and with narrow particle size distributions. The data sets that were composed of green densities of cylindrical pellets were first randomly partitioned into two for training and testing of the ANN models. Based on the training data an ANN model of the packing efficiencies was created with low average error levels (3.36%). Testing of the model was also performed with successfully good average error levels of 3.39%. (c) 2006 Elsevier Ltd. All fights reserved. |
Tanoglu, Metin; Ergun, Yelda Porous nanocomposites prepared from layered clay and PMMA [poly(methyl methacrylate)] Journal Article COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING, 38 (2), pp. 318-322, 2007, ISSN: 1359-835X. @article{ISI:000244008900011, title = {Porous nanocomposites prepared from layered clay and PMMA [poly(methyl methacrylate)]}, author = {Metin Tanoglu and Yelda Ergun}, doi = {10.1016/j.compositesa.2006.04.002}, issn = {1359-835X}, year = {2007}, date = {2007-01-01}, journal = {COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING}, volume = {38}, number = {2}, pages = {318-322}, abstract = {The aim of the present work is the preparation of PMMA based porous nanocomposites that contain clay (montmorillonite, MMT) platelets as reinforcements within the cell walls of the porous structure. To render the clay layers organophilic, MMT was surface treated by an ion exchange reaction between interlayer cations of the clay and ammonium ions of a surfactant. Clay/PMMA based porous nanocomposites were prepared by polymerization of water-in-oil emulsions with and without clay addition. The microstructure and compressive mechanical behavior of the nanocomposites were investigated. The results of mechanical tests showed that the porous systems with the addition of 1 wt.% of organoclay (OMNIT) exhibited a 90% and 50% increase of collapse stress and elastic modulus values, respectively, as compared to neat porous PMMA. (c) 2006 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of the present work is the preparation of PMMA based porous nanocomposites that contain clay (montmorillonite, MMT) platelets as reinforcements within the cell walls of the porous structure. To render the clay layers organophilic, MMT was surface treated by an ion exchange reaction between interlayer cations of the clay and ammonium ions of a surfactant. Clay/PMMA based porous nanocomposites were prepared by polymerization of water-in-oil emulsions with and without clay addition. The microstructure and compressive mechanical behavior of the nanocomposites were investigated. The results of mechanical tests showed that the porous systems with the addition of 1 wt.% of organoclay (OMNIT) exhibited a 90% and 50% increase of collapse stress and elastic modulus values, respectively, as compared to neat porous PMMA. (c) 2006 Elsevier Ltd. All rights reserved. |
2006 |
Celik, E; Gokcen, Z; Azem, Ak N F; Tanoglu, M; Emrullahoglu, O F Processing, characterization and photocatalytic properties of Cu doped TiO2 thin films on glass substrate by sol-gel technique Journal Article MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY, 132 (3), pp. 258-265, 2006, ISSN: 0921-5107. @article{ISI:000240149800005, title = {Processing, characterization and photocatalytic properties of Cu doped TiO2 thin films on glass substrate by sol-gel technique}, author = {E Celik and Z Gokcen and Ak N F Azem and M Tanoglu and O F Emrullahoglu}, doi = {10.1016/j.mseb.2006.03.038}, issn = {0921-5107}, year = {2006}, date = {2006-08-01}, journal = {MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY}, volume = {132}, number = {3}, pages = {258-265}, abstract = {The present paper describes processing, properties and photocatalytic application of Cu doped TiO2 thin films on glass substrate. Cu doped TiO2 coatings were successfully prepared on glass slide substrates using sol-gel method. The obtained solutions exhibit acidic characteristics. The phase structure, thermal, microstructure and surface properties of the coatings were characterized by using XRD, DTA/TG, SEM and AFM. Their adhesion properties and spectroscopic analysis were investigated by a scratch tester and UV-vis spectroscopy. Four different solutions were prepared by changing Cu/Ti ratios. Glass substrates were coated by solutions of Ti-alkoxide, Cu-chloride, glacial acetic acid and isopropanol. The obtained gel films were dried at 300 degrees C for 10 min and subsequently heat-treated at 500 degrees C for 5 min in air. The oxide thin films were annealed at 600 degrees C for 60min in air. TiO2, CuO, Cu4Ti, Ti3O5 and Cu3TiO4 phases were found in the coating. The organic matters were burned at temperatures between 200 and 350 degrees C and TiO2 crystallization was formed at 450 degrees C. The weight loss of the powder during process up to 600 degrees C is approximately 70%. The microstructural observations demonstrated that CuO content was led an improved surface morphology while thickness of the film and surface defects were increased in accordance with number of dipping. According to AFM results, it was found that as the Cu/Ti content increases the surface roughness of the films increases. In addition structural, thermal and microstructural results, it was found that the films of 0.73 ratio have better adhesion strength to the glass substrate among other coatings. The oxide films were found to be active for photocatalytic decomposition of metylene blue. (c) 2006 Published by Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present paper describes processing, properties and photocatalytic application of Cu doped TiO2 thin films on glass substrate. Cu doped TiO2 coatings were successfully prepared on glass slide substrates using sol-gel method. The obtained solutions exhibit acidic characteristics. The phase structure, thermal, microstructure and surface properties of the coatings were characterized by using XRD, DTA/TG, SEM and AFM. Their adhesion properties and spectroscopic analysis were investigated by a scratch tester and UV-vis spectroscopy. Four different solutions were prepared by changing Cu/Ti ratios. Glass substrates were coated by solutions of Ti-alkoxide, Cu-chloride, glacial acetic acid and isopropanol. The obtained gel films were dried at 300 degrees C for 10 min and subsequently heat-treated at 500 degrees C for 5 min in air. The oxide thin films were annealed at 600 degrees C for 60min in air. TiO2, CuO, Cu4Ti, Ti3O5 and Cu3TiO4 phases were found in the coating. The organic matters were burned at temperatures between 200 and 350 degrees C and TiO2 crystallization was formed at 450 degrees C. The weight loss of the powder during process up to 600 degrees C is approximately 70%. The microstructural observations demonstrated that CuO content was led an improved surface morphology while thickness of the film and surface defects were increased in accordance with number of dipping. According to AFM results, it was found that as the Cu/Ti content increases the surface roughness of the films increases. In addition structural, thermal and microstructural results, it was found that the films of 0.73 ratio have better adhesion strength to the glass substrate among other coatings. The oxide films were found to be active for photocatalytic decomposition of metylene blue. (c) 2006 Published by Elsevier B.V. |
Boke, H; Akkurt, S; Ipekoglu, B; Ugurlu, E Characteristics of brick used as aggregate in historic brick-lime mortars and plasters Journal Article CEMENT AND CONCRETE RESEARCH, 36 (6), pp. 1115-1122, 2006, ISSN: 0008-8846. @article{ISI:000238466400015, title = {Characteristics of brick used as aggregate in historic brick-lime mortars and plasters}, author = {H Boke and S Akkurt and B Ipekoglu and E Ugurlu}, doi = {10.1016/j.cemconres.2006.03.011}, issn = {0008-8846}, year = {2006}, date = {2006-06-01}, journal = {CEMENT AND CONCRETE RESEARCH}, volume = {36}, number = {6}, pages = {1115-1122}, abstract = {Mortars and plasters composed of a mixture of brick powder and lime have been used since ancient times due to their hydraulic properties. In this study, raw material compositions, basic physical, mineralogical, microstructural and hydraulic properties of some historic Ottoman Bath brick-lime mortars and plasters were determined by XRD, SEM-EDS, AFM, TGA and chemical analyses. The mineralogical and chemical compositions, microstructures, morphologies and pozzolanicities of the brick powders and fragments used as aggregates in the mortars and plasters were examined to find out the relationship between hydraulic properties of the mortars and the bricks. The characteristics of bricks used in the bath domes were also determined to investigate whether the brick aggregates used in mortar and plasters were prepared from these bricks. The results indicated that the mortars and plasters were hydraulic owing to the presence of crushed brick powders that have good pozzolanicity. The brick powders bad high pozzolanicity because they contained high amounts of calcium-poor clay minerals in their raw materials that were fired at low temperatures. On the other hand, bricks used in the domes had poor pozzolanicity with different mineralogical and chemical compositions from bricks used in mortars and plasters. Based on the results of the analysis, it was thought that the bricks manufactured with high amounts of clays were consciously chosen in the preparation of hydraulic mortars and plasters. (C) 2006 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Mortars and plasters composed of a mixture of brick powder and lime have been used since ancient times due to their hydraulic properties. In this study, raw material compositions, basic physical, mineralogical, microstructural and hydraulic properties of some historic Ottoman Bath brick-lime mortars and plasters were determined by XRD, SEM-EDS, AFM, TGA and chemical analyses. The mineralogical and chemical compositions, microstructures, morphologies and pozzolanicities of the brick powders and fragments used as aggregates in the mortars and plasters were examined to find out the relationship between hydraulic properties of the mortars and the bricks. The characteristics of bricks used in the bath domes were also determined to investigate whether the brick aggregates used in mortar and plasters were prepared from these bricks. The results indicated that the mortars and plasters were hydraulic owing to the presence of crushed brick powders that have good pozzolanicity. The brick powders bad high pozzolanicity because they contained high amounts of calcium-poor clay minerals in their raw materials that were fired at low temperatures. On the other hand, bricks used in the domes had poor pozzolanicity with different mineralogical and chemical compositions from bricks used in mortars and plasters. Based on the results of the analysis, it was thought that the bricks manufactured with high amounts of clays were consciously chosen in the preparation of hydraulic mortars and plasters. (C) 2006 Elsevier Ltd. All rights reserved. |
Celik, E; Yildiz, AY; Azem, NFA; Tanoglu, M; Toparli, M; Emrullahoglu, OF; Ozdemir, I Preparation and characterization of Fe2O3-TiO2 thin films on glass substrate for photocatalytic applications Journal Article MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY, 129 (1-3), pp. 193-199, 2006, ISSN: 0921-5107. @article{ISI:000236952200035, title = {Preparation and characterization of Fe2O3-TiO2 thin films on glass substrate for photocatalytic applications}, author = {E Celik and AY Yildiz and NFA Azem and M Tanoglu and M Toparli and OF Emrullahoglu and I Ozdemir}, doi = {10.1016/j.mseb.2006.01.013}, issn = {0921-5107}, year = {2006}, date = {2006-04-01}, journal = {MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY}, volume = {129}, number = {1-3}, pages = {193-199}, abstract = {Fe2O3-TiO2 coatings were successfully prepared on glass slide substrates using sol-gel method for photocatalytic applications. The phase structure, thermal, microstructure and surface properties of the coatings were extensively characterized by using X-ray diffractometry (XRD), differential thermal analysis/thermograviometry (DTA/TG), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Their adhesion and absorbance properties were investigated by a scratch tester and UV-vis spectroscopy. Four different solutions were prepared by changing Fe/Ti molar ratios. Glass substrates were coated by solutions of Ti-alkoxide, Fe-chloride, glaciel acetic acid and isopropanol. The obtained gel films were dried at 300 degrees C for 10 min and subsequently heat-treated at 500 degrees C for 5 min in air. The oxide thin films were annealed at 600 degrees C for 60 min in air. The influence of Fe3+ concentration and number of layers on structure of the films was established. In addition, XRD results revealed that Fe2O3-TiO2 films composed of TiO2, Fe2Ti3O9, Ti3O5 and Fe3O4 phases. According to DTA/TG result, it was determined that endothermic and exothermic reactions were formed at temperatures between 80 and 650 degrees C due to solvent removal, combustion of carbon based materials and oxidation of Fe and Ti. SEM observations exhibited that the coating structure becomes more homogeneous depending on an increase of Fe/Ti molar ratios and thus a regular surface morphology forms with increasing Fe/Ti ratio. It was also seen that as the Fe/Ti ratio increases the surface roughness of the films increases. Critical adhesion force of thin films with Fe/Ti ratio of 0, 0.07, 0.18 and 0.73 were found to be 9, 25, 28 and 21 mN, respectively. The methylene blue solutions photocatalyzed by TiO2 based thin films shows characteristic absorption bands at 420 nm. (c) 2006 Elsevier B.V. All fights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fe2O3-TiO2 coatings were successfully prepared on glass slide substrates using sol-gel method for photocatalytic applications. The phase structure, thermal, microstructure and surface properties of the coatings were extensively characterized by using X-ray diffractometry (XRD), differential thermal analysis/thermograviometry (DTA/TG), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Their adhesion and absorbance properties were investigated by a scratch tester and UV-vis spectroscopy. Four different solutions were prepared by changing Fe/Ti molar ratios. Glass substrates were coated by solutions of Ti-alkoxide, Fe-chloride, glaciel acetic acid and isopropanol. The obtained gel films were dried at 300 degrees C for 10 min and subsequently heat-treated at 500 degrees C for 5 min in air. The oxide thin films were annealed at 600 degrees C for 60 min in air. The influence of Fe3+ concentration and number of layers on structure of the films was established. In addition, XRD results revealed that Fe2O3-TiO2 films composed of TiO2, Fe2Ti3O9, Ti3O5 and Fe3O4 phases. According to DTA/TG result, it was determined that endothermic and exothermic reactions were formed at temperatures between 80 and 650 degrees C due to solvent removal, combustion of carbon based materials and oxidation of Fe and Ti. SEM observations exhibited that the coating structure becomes more homogeneous depending on an increase of Fe/Ti molar ratios and thus a regular surface morphology forms with increasing Fe/Ti ratio. It was also seen that as the Fe/Ti ratio increases the surface roughness of the films increases. Critical adhesion force of thin films with Fe/Ti ratio of 0, 0.07, 0.18 and 0.73 were found to be 9, 25, 28 and 21 mN, respectively. The methylene blue solutions photocatalyzed by TiO2 based thin films shows characteristic absorption bands at 420 nm. (c) 2006 Elsevier B.V. All fights reserved. |
Yalamac, Emre; Akkurt, Sedat Additive and intensive grinding effects on the synthesis of cordierite Journal Article CERAMICS INTERNATIONAL, 32 (7), pp. 825-832, 2006, ISSN: 0272-8842. @article{ISI:000240301900017, title = {Additive and intensive grinding effects on the synthesis of cordierite}, author = {Emre Yalamac and Sedat Akkurt}, doi = {10.1016/j.ceramint.2005.06.006}, issn = {0272-8842}, year = {2006}, date = {2006-01-01}, journal = {CERAMICS INTERNATIONAL}, volume = {32}, number = {7}, pages = {825-832}, abstract = {Cordierite was mechanochemically synthesized by mixing proper amounts of kaolin, talc and Al(OH)(3). Full factorial experiments were planned, conducted, and the results were analyzed by the use of statistical techniques in order to understand the effects of process variables on the amount of synthesized product. The powder products were analyzed by XRD, DTA, and SEM-EDS. As a result of the statistical analysis, temperature was found to be the most important factor. Based on XRD peak intensity measurements, the cordierite mixture was completely amorphized by grinding at 300 rpm for 60 min. Cordierite was successfully produced at temperatures as low as 1150 degrees C by using the mixture after intensive grinding. The combined effect of magnesium borate additive and grinding on cordierite synthesis was also studied. These factors successfully decreased the synthesis temperature down to 1000 degrees C. (c) 2005 Elsevier Ltd and Techna Group S.r.l. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cordierite was mechanochemically synthesized by mixing proper amounts of kaolin, talc and Al(OH)(3). Full factorial experiments were planned, conducted, and the results were analyzed by the use of statistical techniques in order to understand the effects of process variables on the amount of synthesized product. The powder products were analyzed by XRD, DTA, and SEM-EDS. As a result of the statistical analysis, temperature was found to be the most important factor. Based on XRD peak intensity measurements, the cordierite mixture was completely amorphized by grinding at 300 rpm for 60 min. Cordierite was successfully produced at temperatures as low as 1150 degrees C by using the mixture after intensive grinding. The combined effect of magnesium borate additive and grinding on cordierite synthesis was also studied. These factors successfully decreased the synthesis temperature down to 1000 degrees C. (c) 2005 Elsevier Ltd and Techna Group S.r.l. All rights reserved. |
Akkas, Deniz H; Ovecoglu, Lutfi M; Tanoglu, Metin Silicon oxycarbide-based composites produced from pyrolysis of polysiloxanes with active Ti filler Journal Article JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 26 (15), pp. 3441-3449, 2006, ISSN: 0955-2219. @article{ISI:000241086000049, title = {Silicon oxycarbide-based composites produced from pyrolysis of polysiloxanes with active Ti filler}, author = {Deniz H Akkas and Lutfi M Ovecoglu and Metin Tanoglu}, doi = {10.1016/j.jeurceramsoc.2005.08.017}, issn = {0955-2219}, year = {2006}, date = {2006-01-01}, journal = {JOURNAL OF THE EUROPEAN CERAMIC SOCIETY}, volume = {26}, number = {15}, pages = {3441-3449}, abstract = {Phenyl (PPS) and methyl (PMS) containing polysiloxanes were pyrolyzed at elevated temperatures (900-1500 degrees C) under argon atmosphere to investigate the phase developments within the polymers. It was found that pyrolysis of the polymers under inert atmosphere up to 1300 degrees C leads to amorphous silicon oxycarbide (SiOxCy) ceramics. Conversions at higher temperatures results in the transformations into the crystalline beta-SiC phases. Ceramic matrix composites (CMCs) were developed based on the active filler controlled pyrolysis (AFCOP) of polysiloxanes with active Ti filler additions. CMC monoliths were prepared with 60-80 wt.% of active Ti particulates blended into polymer precursors. Green bodies of the composites were made by warm pressing under 15 MPa pressure and ceramics were obtained by pyrolysis at elevated temperatures between 900 and 1500 degrees C under argon atmosphere. The results showed that due to the incorporation of active Ti fillers, formation of crystalline phases such as TiC, TiSi, and TiO occured within the amorphous matrix due to the reactions between the Ti and the polymer decomposition products. The microstructural and mechanical characterization results of the composites are presented within the paper. (c) 2005 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Phenyl (PPS) and methyl (PMS) containing polysiloxanes were pyrolyzed at elevated temperatures (900-1500 degrees C) under argon atmosphere to investigate the phase developments within the polymers. It was found that pyrolysis of the polymers under inert atmosphere up to 1300 degrees C leads to amorphous silicon oxycarbide (SiOxCy) ceramics. Conversions at higher temperatures results in the transformations into the crystalline beta-SiC phases. Ceramic matrix composites (CMCs) were developed based on the active filler controlled pyrolysis (AFCOP) of polysiloxanes with active Ti filler additions. CMC monoliths were prepared with 60-80 wt.% of active Ti particulates blended into polymer precursors. Green bodies of the composites were made by warm pressing under 15 MPa pressure and ceramics were obtained by pyrolysis at elevated temperatures between 900 and 1500 degrees C under argon atmosphere. The results showed that due to the incorporation of active Ti fillers, formation of crystalline phases such as TiC, TiSi, and TiO occured within the amorphous matrix due to the reactions between the Ti and the polymer decomposition products. The microstructural and mechanical characterization results of the composites are presented within the paper. (c) 2005 Elsevier Ltd. All rights reserved. |
2005 |
Seyhan, AT; Tayfur, G; Karakurt, M; Tanoglu, M Artificial neural network (ANN) prediction of compressive strength of VARTM processed polymer composites Journal Article COMPUTATIONAL MATERIALS SCIENCE, 34 (1), pp. 99-105, 2005, ISSN: 0927-0256. @article{ISI:000228943700009, title = {Artificial neural network (ANN) prediction of compressive strength of VARTM processed polymer composites}, author = {AT Seyhan and G Tayfur and M Karakurt and M Tanoglu}, doi = {10.1016/j.commatsci.2004.11.001}, issn = {0927-0256}, year = {2005}, date = {2005-08-01}, journal = {COMPUTATIONAL MATERIALS SCIENCE}, volume = {34}, number = {1}, pages = {99-105}, abstract = {A three layer feed forward artificial neural network (ANN) model having three input neurons, one output neuron and two hidden neurons was developed to predict the ply-lay up compressive strength of VARTM processed E-glass/ polyester composites. The composites were manufactured using fabric preforms consolidated with 0, 3 and 6 wt.% of thermoplastic binder. The learning of ANN was accomplished by a backpropagation algorithm. A good agreement between the measured and the predicted values was obtained. Testing of the model was done within low average error levels of 3.28%. Furthermore, the predictions of ANN model were compared with those obtained from a multi-linear regression (MLR) model. It was found that ANN model has better predictions than MLR model for the experimental data. Also, the ANN model was subjected to a sensitivity analysis to obtain its response. As a result, the ANN model was found to have an ability to yield a desired level of ply-lay up compressive strength values for the composites processed with the addition of the thermoplastic binder. (c) 2004 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A three layer feed forward artificial neural network (ANN) model having three input neurons, one output neuron and two hidden neurons was developed to predict the ply-lay up compressive strength of VARTM processed E-glass/ polyester composites. The composites were manufactured using fabric preforms consolidated with 0, 3 and 6 wt.% of thermoplastic binder. The learning of ANN was accomplished by a backpropagation algorithm. A good agreement between the measured and the predicted values was obtained. Testing of the model was done within low average error levels of 3.28%. Furthermore, the predictions of ANN model were compared with those obtained from a multi-linear regression (MLR) model. It was found that ANN model has better predictions than MLR model for the experimental data. Also, the ANN model was subjected to a sensitivity analysis to obtain its response. As a result, the ANN model was found to have an ability to yield a desired level of ply-lay up compressive strength values for the composites processed with the addition of the thermoplastic binder. (c) 2004 Elsevier B.V. All rights reserved. |
Yalcintas, M; Akkurt, S Artificial neural networks applications in building energy predictions and a case study for tropical climates Journal Article INTERNATIONAL JOURNAL OF ENERGY RESEARCH, 29 (10), pp. 891-901, 2005, ISSN: 0363-907X. @article{ISI:000231320300003, title = {Artificial neural networks applications in building energy predictions and a case study for tropical climates}, author = {M Yalcintas and S Akkurt}, doi = {10.1002/er.1105}, issn = {0363-907X}, year = {2005}, date = {2005-08-01}, journal = {INTERNATIONAL JOURNAL OF ENERGY RESEARCH}, volume = {29}, number = {10}, pages = {891-901}, abstract = {This study presents artificial neural network (ANN) methods in building energy use predictions. Applications of the ANN methods in energy audits and energy savings predictions due to building retrofits are emphasized. A generalized ANN model that can be applied to any building type with minor modifications would be a very useful tool for building engineers. ANN methods offer faster learning time, simplicity in analysis and adaptability to seasonal climate variations and changes in the building's energy use when compared to other statistical and simulation models. The model herein is presented for predicting chiller plant energy use in tropical climates with small seasonal and daily variations. It was successfully created based on both climatic and chiller data. The average absolute training error for the model was 9.7% while the testing error was 10.0%. This indicates that the model can successfully predict the particular chiller energy consumption in a tropical climate. Copyright (c) 2005 John Wiley & Sons, Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study presents artificial neural network (ANN) methods in building energy use predictions. Applications of the ANN methods in energy audits and energy savings predictions due to building retrofits are emphasized. A generalized ANN model that can be applied to any building type with minor modifications would be a very useful tool for building engineers. ANN methods offer faster learning time, simplicity in analysis and adaptability to seasonal climate variations and changes in the building's energy use when compared to other statistical and simulation models. The model herein is presented for predicting chiller plant energy use in tropical climates with small seasonal and daily variations. It was successfully created based on both climatic and chiller data. The average absolute training error for the model was 9.7% while the testing error was 10.0%. This indicates that the model can successfully predict the particular chiller energy consumption in a tropical climate. Copyright (c) 2005 John Wiley & Sons, Ltd. |
2004 |
Aliyev, MI; Khalilova, AA; Arasly, DH; Rahimov, RN; Tanoglu, M; Ozyuzer, L Strain gauges of GaSb-FeGa1.3 eutectic composites Journal Article APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 79 (8), pp. 2075-2078, 2004, ISSN: 0947-8396. @article{ISI:000224387200044, title = {Strain gauges of GaSb-FeGa1.3 eutectic composites}, author = {MI Aliyev and AA Khalilova and DH Arasly and RN Rahimov and M Tanoglu and L Ozyuzer}, doi = {10.1007/s00339-004-2870-0}, issn = {0947-8396}, year = {2004}, date = {2004-12-01}, journal = {APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING}, volume = {79}, number = {8}, pages = {2075-2078}, abstract = {A needle-shaped metallic FeGa1.3 phase oriented in a specific direction and uniformly distributed within a GaSb matrix was grown by a vertical Bridgman method. Strain-gauge characteristics, such as strain-sensitivity coefficient (S), temperature coefficient of strain sensitivity (TCS) and temperature coefficient of resistance, of GaSb and GaSb-FeGa1.3 eutectic alloy have been investigated in the range of 200 to 400 K under deformation up to strains of 1.3x10(-3). The value of S of the GaSb-FeGa1.3 composition is measured to be 40+/-5 and its TCS is about 0.2% deg(-1) when the current is perpendicular to the needles and the needles are parallel to the plane of the gauge substrate. The strain-sensitivity characteristics are linear and hysteresis free in the investigated temperature range in the aforementioned direction. It was found that GaSb-FeGa1.3-based strain gauges possess better deformation characteristics than GaSb-based gauges.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A needle-shaped metallic FeGa1.3 phase oriented in a specific direction and uniformly distributed within a GaSb matrix was grown by a vertical Bridgman method. Strain-gauge characteristics, such as strain-sensitivity coefficient (S), temperature coefficient of strain sensitivity (TCS) and temperature coefficient of resistance, of GaSb and GaSb-FeGa1.3 eutectic alloy have been investigated in the range of 200 to 400 K under deformation up to strains of 1.3x10(-3). The value of S of the GaSb-FeGa1.3 composition is measured to be 40+/-5 and its TCS is about 0.2% deg(-1) when the current is perpendicular to the needles and the needles are parallel to the plane of the gauge substrate. The strain-sensitivity characteristics are linear and hysteresis free in the investigated temperature range in the aforementioned direction. It was found that GaSb-FeGa1.3-based strain gauges possess better deformation characteristics than GaSb-based gauges. |
Ergun, Y; Dirier, C; Tanoglu, M Polymethyl methacrylate based open-cell porous plastics for high-pressure ceramic casting Journal Article MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 385 (1-2), pp. 279-285, 2004, ISSN: 0921-5093. @article{ISI:000224822000035, title = {Polymethyl methacrylate based open-cell porous plastics for high-pressure ceramic casting}, author = {Y Ergun and C Dirier and M Tanoglu}, doi = {10.1016/j.msea.2004.07.014}, issn = {0921-5093}, year = {2004}, date = {2004-11-01}, journal = {MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, volume = {385}, number = {1-2}, pages = {279-285}, abstract = {The aim of the present study is to investigate the microstructure-property relation in polymethyl methacrylate (PMMA)-based porous mould materials used for high-pressure casting of ceramic articles. For this purpose, porous plastic materials were produced by the polymerization of water-in-oil emulsions with various compositions of emulsion constituents and particle sizes of the filler PMMA beads. Pore morphology, porosity and water permeability of the materials were measured. The compressive stress-strain behavior, collapse stress and elastic modulus values of the macroporous materials were determined by performing compressive mechanical testing. Fracture toughness values of the materials were also measured using the single-edge notched bending method. The results showed that the concentration of emulsion constituents and PMMA bead sizes has significant effects on the pore morphology, porosity, water permeability and mechanical properties of the porous plastics. (C) 2004 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of the present study is to investigate the microstructure-property relation in polymethyl methacrylate (PMMA)-based porous mould materials used for high-pressure casting of ceramic articles. For this purpose, porous plastic materials were produced by the polymerization of water-in-oil emulsions with various compositions of emulsion constituents and particle sizes of the filler PMMA beads. Pore morphology, porosity and water permeability of the materials were measured. The compressive stress-strain behavior, collapse stress and elastic modulus values of the macroporous materials were determined by performing compressive mechanical testing. Fracture toughness values of the materials were also measured using the single-edge notched bending method. The results showed that the concentration of emulsion constituents and PMMA bead sizes has significant effects on the pore morphology, porosity, water permeability and mechanical properties of the porous plastics. (C) 2004 Elsevier B.V. All rights reserved. |
Akkurt, S; Tayfur, G; Can, S Fuzzy logic model for the prediction of cement compressive strength Journal Article CEMENT AND CONCRETE RESEARCH, 34 (8), pp. 1429-1433, 2004, ISSN: 0008-8846. @article{ISI:000224017600016, title = {Fuzzy logic model for the prediction of cement compressive strength}, author = {S Akkurt and G Tayfur and S Can}, doi = {10.1016/j.cemconres.2004.01.020}, issn = {0008-8846}, year = {2004}, date = {2004-08-01}, journal = {CEMENT AND CONCRETE RESEARCH}, volume = {34}, number = {8}, pages = {1429-1433}, abstract = {A fuzzy logic prediction model for the 28-day compressive strength of cement mortar under standard curing conditions was created. Data collected from a cement plant were used in the model construction and testing. The input variables of alkali, Blaine, SO3, and C3S and the output variable of 28-day cement strength were fuzzified by the use of artificial neural networks (ANNs), and triangular membership functions were employed for the fuzzy subsets. The Mamdani fuzzy rules relating the input variables to the output variable were created by the ANN model and were laid out in the If-Then format. Product (prod) inference operator and the centre of gravity (COG; centroid) defuzzification methods were employed. The prediction of 50 sets of the 28-day cement strength data by the developed fuzzy model was quite satisfactory. The average percentage error levels in the fuzzy model were successfully low (2.69%). The model was compared with the ANN model for its error levels and ease of application. The results indicated that through the application of fuzzy logic algorithm, a more user friendly and more explicit model than the ANNs could be produced within successfully low error margins. (C) 2004 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A fuzzy logic prediction model for the 28-day compressive strength of cement mortar under standard curing conditions was created. Data collected from a cement plant were used in the model construction and testing. The input variables of alkali, Blaine, SO3, and C3S and the output variable of 28-day cement strength were fuzzified by the use of artificial neural networks (ANNs), and triangular membership functions were employed for the fuzzy subsets. The Mamdani fuzzy rules relating the input variables to the output variable were created by the ANN model and were laid out in the If-Then format. Product (prod) inference operator and the centre of gravity (COG; centroid) defuzzification methods were employed. The prediction of 50 sets of the 28-day cement strength data by the developed fuzzy model was quite satisfactory. The average percentage error levels in the fuzzy model were successfully low (2.69%). The model was compared with the ANN model for its error levels and ease of application. The results indicated that through the application of fuzzy logic algorithm, a more user friendly and more explicit model than the ANNs could be produced within successfully low error margins. (C) 2004 Elsevier Ltd. All rights reserved. |
Akkurt, S; Ozcan, S ANN model predicts floor tile properties Journal Article AMERICAN CERAMIC SOCIETY BULLETIN, 83 (2), pp. 9101-9109, 2004. @article{ISI:000188920500042, title = {ANN model predicts floor tile properties}, author = {S Akkurt and S Ozcan}, year = {2004}, date = {2004-02-01}, journal = {AMERICAN CERAMIC SOCIETY BULLETIN}, volume = {83}, number = {2}, pages = {9101-9109}, abstract = {World production of ceramic tile has been increasing at a steep rate during the past 15 years. 1–3 Concise, well-defined technical qualities—such as dimensional stability, warping, water absorption, flex-ural strength, linear thermal expansion coefficient, ther-mal shock resistance, frost resistance, crazing resistance, abrasion resistance, scratch hardness, chemical resist-ance and stain resistance—have to be combined with desired aesthetic features to produce a marketable product. 4 Competition in the market requires maximum produc-tivity, quality-and quantity-wise, at a minimum cost. This has led to many process innovations, 5–7 including replacement of tunnel kilns with fast-firing roller kilns. Nevertheless, strict control of processing parameters is often a prerequisite to efficient production. The effects of processing parameters on the final prod-uct properties have been widely studied in the litera-ture. Many of these works have involved the effects of raw-material types, 8 proportions, 9 chemistry, 10 size dis-tributions 11–14 and packing 15–17 in addition to studies on drying 13,18,19 and firing 18,20 processes. More recently, research efforts have concentrated on the use of wastes—such as iron and other metallurgical slag and flotation products—in tile composition. 21-23 Few attempts have been made to model these parameters to create an overall tile process model. For example, mathematical models exist for the correlation ISSN = 0002-7812}, keywords = {}, pubstate = {published}, tppubtype = {article} } World production of ceramic tile has been increasing at a steep rate during the past 15 years. 1–3 Concise, well-defined technical qualities—such as dimensional stability, warping, water absorption, flex-ural strength, linear thermal expansion coefficient, ther-mal shock resistance, frost resistance, crazing resistance, abrasion resistance, scratch hardness, chemical resist-ance and stain resistance—have to be combined with desired aesthetic features to produce a marketable product. 4 Competition in the market requires maximum produc-tivity, quality-and quantity-wise, at a minimum cost. This has led to many process innovations, 5–7 including replacement of tunnel kilns with fast-firing roller kilns. Nevertheless, strict control of processing parameters is often a prerequisite to efficient production. The effects of processing parameters on the final prod-uct properties have been widely studied in the litera-ture. Many of these works have involved the effects of raw-material types, 8 proportions, 9 chemistry, 10 size dis-tributions 11–14 and packing 15–17 in addition to studies on drying 13,18,19 and firing 18,20 processes. More recently, research efforts have concentrated on the use of wastes—such as iron and other metallurgical slag and flotation products—in tile composition. 21-23 Few attempts have been made to model these parameters to create an overall tile process model. For example, mathematical models exist for the correlation ISSN = 0002-7812 |
Boke, H; Akkurt, S; Ozdemir, S; Gokturk, EH; Saltik, ENC Quantification of CaCO3-CaSO3 center dot 0.5H(2)O-CaSO4 center dot 2H(2)O mixtures by FTIR analysis and its ANN model Journal Article MATERIALS LETTERS, 58 (5), pp. 723-726, 2004, ISSN: 0167-577X. @article{ISI:000188216300035, title = {Quantification of CaCO3-CaSO3 center dot 0.5H(2)O-CaSO4 center dot 2H(2)O mixtures by FTIR analysis and its ANN model}, author = {H Boke and S Akkurt and S Ozdemir and EH Gokturk and ENC Saltik}, doi = {10.1016/j.matlet.2003.07.008}, issn = {0167-577X}, year = {2004}, date = {2004-02-01}, journal = {MATERIALS LETTERS}, volume = {58}, number = {5}, pages = {723-726}, abstract = {A new quantitative analysis method for mixtures of calcium carbonate (CaCO3), calcium sulphite hemihydrate (CaSO3.1/2H(2)O) and gypsum (CaSO4.2H(2)O) by FTIR spectroscopy is developed. The method involves the FTIR analysis of powder mixtures of several compositions on KBr disc specimens. Intensities of the resulting absorbance peaks for CaCO3, CaSO3.1/2H(2)O and CaSO4.2H(2)O at 1453, 980, 1146 cm(-1) were used as input data for an artificial neural network (ANN) model, the output being the weight percent compositions of the mixtures. The training and testing data were randomly separated from the complete original data set. Testing of the model was done with successfully low-average error levels. The utility of the model is in the potential ability to use FTIR spectrum to predict the proportions of the three substances in unknown mixtures. (C) 2003 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new quantitative analysis method for mixtures of calcium carbonate (CaCO3), calcium sulphite hemihydrate (CaSO3.1/2H(2)O) and gypsum (CaSO4.2H(2)O) by FTIR spectroscopy is developed. The method involves the FTIR analysis of powder mixtures of several compositions on KBr disc specimens. Intensities of the resulting absorbance peaks for CaCO3, CaSO3.1/2H(2)O and CaSO4.2H(2)O at 1453, 980, 1146 cm(-1) were used as input data for an artificial neural network (ANN) model, the output being the weight percent compositions of the mixtures. The training and testing data were randomly separated from the complete original data set. Testing of the model was done with successfully low-average error levels. The utility of the model is in the potential ability to use FTIR spectrum to predict the proportions of the three substances in unknown mixtures. (C) 2003 Elsevier B.V. All rights reserved. |
2003 |
Tanoglu, M; Seyhan, AT Compressive mechanical behaviour of E-glass/polyester composite laminates tailored with a thermoplastic preforming binder Journal Article MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 363 (1-2), pp. 335-344, 2003, ISSN: 0921-5093. @article{ISI:000186851000042, title = {Compressive mechanical behaviour of E-glass/polyester composite laminates tailored with a thermoplastic preforming binder}, author = {M Tanoglu and AT Seyhan}, doi = {10.1016/j.msea.2003.08.005}, issn = {0921-5093}, year = {2003}, date = {2003-12-01}, journal = {MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, volume = {363}, number = {1-2}, pages = {335-344}, abstract = {Compressive mechanical behaviour and failure modes of E (electrical)-glass/polyester composite laminates tailored with a thermoplastic preforming polyester binder were investigated under ply-lay up and in-plane loading directions. Fiber preforms with various amount of the binder were consolidated under heat and pressure. The preform compaction experiments were performed by applying compressive pressure to the preforms, and the average thickness as a function of pressure was measured. It was found that the highest compaction of the preforms and therefore the highest fiber volume fraction can be obtained with 3 wt.% of the binder. Further increase of the amount of binder decreases the degree of compaction. Composite panels were fabricated by vacuum-assisted resin transfer molding using fabric preforms with various binder concentrations. The present investigation reveals that there are considerable effects of the binder on the compressive mechanical behaviour of the composites. Compression testing of the composites showed that the average strength values are in the range of 400-600 and 150-300 MPa for ply-lay up and in-plane directions, respectively. Also, both the strength and modulus values increase up to 3 wt.% of the binder, and these values decrease with further addition of the binder. Scanning electron microscopy showed that failure modes of the composites are altered significantly by the presence of the binder. Furthermore, the interaction between the binder and the reacting resin was followed to determine the extent of the binder dissolution and its effects on the viscosity of the resin and the mechanical behaviour of the matrix polymer. The results indicate that there is a partial dissolution of the binder within the matrix resin. (C) 2003 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Compressive mechanical behaviour and failure modes of E (electrical)-glass/polyester composite laminates tailored with a thermoplastic preforming polyester binder were investigated under ply-lay up and in-plane loading directions. Fiber preforms with various amount of the binder were consolidated under heat and pressure. The preform compaction experiments were performed by applying compressive pressure to the preforms, and the average thickness as a function of pressure was measured. It was found that the highest compaction of the preforms and therefore the highest fiber volume fraction can be obtained with 3 wt.% of the binder. Further increase of the amount of binder decreases the degree of compaction. Composite panels were fabricated by vacuum-assisted resin transfer molding using fabric preforms with various binder concentrations. The present investigation reveals that there are considerable effects of the binder on the compressive mechanical behaviour of the composites. Compression testing of the composites showed that the average strength values are in the range of 400-600 and 150-300 MPa for ply-lay up and in-plane directions, respectively. Also, both the strength and modulus values increase up to 3 wt.% of the binder, and these values decrease with further addition of the binder. Scanning electron microscopy showed that failure modes of the composites are altered significantly by the presence of the binder. Furthermore, the interaction between the binder and the reacting resin was followed to determine the extent of the binder dissolution and its effects on the viscosity of the resin and the mechanical behaviour of the matrix polymer. The results indicate that there is a partial dissolution of the binder within the matrix resin. (C) 2003 Elsevier B.V. All rights reserved. |
Aliyev, MI; Khalilova, AA; Arasly, DH; Rahimov, RN; Tanoglu, M; Ozyuzer, L Features of electron and phonon processes in GaSb-FeGa1.3 eutectics Journal Article JOURNAL OF PHYSICS D-APPLIED PHYSICS, 36 (21), pp. 2627-2633, 2003, ISSN: 0022-3727. @article{ISI:000186845900007, title = {Features of electron and phonon processes in GaSb-FeGa1.3 eutectics}, author = {MI Aliyev and AA Khalilova and DH Arasly and RN Rahimov and M Tanoglu and L Ozyuzer}, doi = {10.1088/0022-3727/36/21/005}, issn = {0022-3727}, year = {2003}, date = {2003-11-01}, journal = {JOURNAL OF PHYSICS D-APPLIED PHYSICS}, volume = {36}, number = {21}, pages = {2627-2633}, abstract = {Eutectic alloys of GaSb-FeGa1.3 were prepared by the vertical Bridgman method. A microstructure with the needle-shaped metallic FeGa1.3 phase oriented in a specific direction and uniformly distributed within the GaSb matrix was obtained. In GaSb-FeGa1.3 eutectics, the electrical and thermal conductivity, thermal diffusivity, thermoelectric power and Hall coefficients were investigated in a wide temperature range. These properties were measured at different mutual directions of current, thermal flow, magnetic field and metal phase inclusions. The influence of metallic inclusions on these properties was revealed and the distinctive characteristics of electron and phonon processes were established.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Eutectic alloys of GaSb-FeGa1.3 were prepared by the vertical Bridgman method. A microstructure with the needle-shaped metallic FeGa1.3 phase oriented in a specific direction and uniformly distributed within the GaSb matrix was obtained. In GaSb-FeGa1.3 eutectics, the electrical and thermal conductivity, thermal diffusivity, thermoelectric power and Hall coefficients were investigated in a wide temperature range. These properties were measured at different mutual directions of current, thermal flow, magnetic field and metal phase inclusions. The influence of metallic inclusions on these properties was revealed and the distinctive characteristics of electron and phonon processes were established. |
Boke, H; Akkurt, S Ettringite formation in historic bath brick-lime plasters Journal Article CEMENT AND CONCRETE RESEARCH, 33 (9), pp. 1457-1464, 2003, ISSN: 0008-8846. @article{ISI:000220484700022, title = {Ettringite formation in historic bath brick-lime plasters}, author = {H Boke and S Akkurt}, doi = {10.1016/S0008-8846(03)00094-2}, issn = {0008-8846}, year = {2003}, date = {2003-09-01}, journal = {CEMENT AND CONCRETE RESEARCH}, volume = {33}, number = {9}, pages = {1457-1464}, abstract = {Two types of historic hydraulic brick-lime plasters from a selected Ottoman bath are examined to characterize their technology and the appropriateness of their use in bath. The first type of plaster is original and structurally sound, while the historic repair plaster is the second type and is found to have deteriorated despite being exposed to the same environment. This difference is investigated by comparing their raw material compositions and the pozzolanic activities of the brick powders used in the plasters. Although these results showed no significant differences, ettringite crystals are detected in the historic repair ones by XRD, FTIR, and SEM-EDS analysis. The repair plaster may have lost its integrity owing to the expansion generated by the growth of ettringite crystals in the plaster. In this study, the ettringite formation is discussed in relation to hydration reaction products of lime-brick plasters, possible sources of gypsum, and the climatic conditions of historic bath building. (C) 2003 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two types of historic hydraulic brick-lime plasters from a selected Ottoman bath are examined to characterize their technology and the appropriateness of their use in bath. The first type of plaster is original and structurally sound, while the historic repair plaster is the second type and is found to have deteriorated despite being exposed to the same environment. This difference is investigated by comparing their raw material compositions and the pozzolanic activities of the brick powders used in the plasters. Although these results showed no significant differences, ettringite crystals are detected in the historic repair ones by XRD, FTIR, and SEM-EDS analysis. The repair plaster may have lost its integrity owing to the expansion generated by the growth of ettringite crystals in the plaster. In this study, the ettringite formation is discussed in relation to hydration reaction products of lime-brick plasters, possible sources of gypsum, and the climatic conditions of historic bath building. (C) 2003 Elsevier Ltd. All rights reserved. |
Akkurt, S; Ozdemir, S; Tayfur, G; Akyol, B The use of GA-ANNs in the modelling of compressive strength of cement mortar Journal Article CEMENT AND CONCRETE RESEARCH, 33 (7), pp. 973-979, 2003, ISSN: 0008-8846. @article{ISI:000183190600005, title = {The use of GA-ANNs in the modelling of compressive strength of cement mortar}, author = {S Akkurt and S Ozdemir and G Tayfur and B Akyol}, doi = {10.1016/S0008-8846(03)00006-1}, issn = {0008-8846}, year = {2003}, date = {2003-07-01}, journal = {CEMENT AND CONCRETE RESEARCH}, volume = {33}, number = {7}, pages = {973-979}, abstract = {In this paper, results of a project aimed at modelling the compressive strength of cement mortar under standard curing conditions are reported. Plant data were collected for 6 months for the chemical and physical properties of the cement that were used in model construction and testing. The training and testing data were separated from the complete original data set by the use of genetic algorithms (GAs). A GA-artificial neural network (ANN) model based on the training data of the cement strength was created. Testing of the model was also done within low average error levels (2.24%). The model was subjected to sensitivity analysis to predict the response of the system to different values of the factors affecting the strength. The plots obtained after sensitivity analysis indicated that increasing the amount Of C3S, SO3 and surface area led to increased strength within the limits of the model. C2S decreased the strength whereas C(3)A decreased or increased the strength depending on the SO3 level. Because of the limited data range used for training, the prediction results were good only within the same range. The utility of the model is in the potential ability to control processing parameters to yield the desired strength levels and in providing information regarding the most favourable experimental conditions to obtain maximum compressive strength. (C) 2003 Elsevier Science Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, results of a project aimed at modelling the compressive strength of cement mortar under standard curing conditions are reported. Plant data were collected for 6 months for the chemical and physical properties of the cement that were used in model construction and testing. The training and testing data were separated from the complete original data set by the use of genetic algorithms (GAs). A GA-artificial neural network (ANN) model based on the training data of the cement strength was created. Testing of the model was also done within low average error levels (2.24%). The model was subjected to sensitivity analysis to predict the response of the system to different values of the factors affecting the strength. The plots obtained after sensitivity analysis indicated that increasing the amount Of C3S, SO3 and surface area led to increased strength within the limits of the model. C2S decreased the strength whereas C(3)A decreased or increased the strength depending on the SO3 level. Because of the limited data range used for training, the prediction results were good only within the same range. The utility of the model is in the potential ability to control processing parameters to yield the desired strength levels and in providing information regarding the most favourable experimental conditions to obtain maximum compressive strength. (C) 2003 Elsevier Science Ltd. All rights reserved. |
Akkurt, S; Leigh, HD Corrosion of MgO-C ladle refractories Journal Article AMERICAN CERAMIC SOCIETY BULLETIN, 82 (5), pp. 32-40B, 2003, ISSN: 0002-7812. @article{ISI:000182912700043, title = {Corrosion of MgO-C ladle refractories}, author = {S Akkurt and HD Leigh}, issn = {0002-7812}, year = {2003}, date = {2003-05-01}, journal = {AMERICAN CERAMIC SOCIETY BULLETIN}, volume = {82}, number = {5}, pages = {32-40B}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Tanoglu, M; Seyhan, AT INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES, 23 (1), pp. 1-8, 2003, ISSN: 0143-7496. @article{ISI:000181503100001, title = {Investigating the effects of a polyester preforming binder on the mechanical and ballistic performance of E-glass fiber reinforced polyester composites}, author = {M Tanoglu and AT Seyhan}, doi = {10.1016/S0143-7496(02)00061-1}, issn = {0143-7496}, year = {2003}, date = {2003-02-01}, journal = {INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES}, volume = {23}, number = {1}, pages = {1-8}, abstract = {An experimental investigation was carried out to determine the effects of a preforming binder on the mechanical properties and ballistic performance of E-glass-fiber/polyester composite systems. The glass preforms were consolidated by application of heat and pressure over plies of the glass fabrics coated with various concentrations of a thermoplastic polyester binder. The peel strength of the preforms with various binder content was measured and the highest peel strength was obtained from preforms prepared with about 9 wt% of the binder. Composite laminates with and without binder were fabricated using VARTM technique and the effects of the binder on the composite mechanical properties were evaluated. It was found that the flexural strength and mode I interlaminar fracture toughness decreases by 15% and 40%, respectively, due to the presence of 3 wt% of the binder. Ballistic test was performed on E-glass/polyester composite panels using 1.1-g fragment-simulating projectiles and it was found that the binder amount has some considerable effect on the damage extension of the impacted composites. The results showed that the preforming binder has significant potential to tailor composite properties. (C) 2003 Elsevier Science Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An experimental investigation was carried out to determine the effects of a preforming binder on the mechanical properties and ballistic performance of E-glass-fiber/polyester composite systems. The glass preforms were consolidated by application of heat and pressure over plies of the glass fabrics coated with various concentrations of a thermoplastic polyester binder. The peel strength of the preforms with various binder content was measured and the highest peel strength was obtained from preforms prepared with about 9 wt% of the binder. Composite laminates with and without binder were fabricated using VARTM technique and the effects of the binder on the composite mechanical properties were evaluated. It was found that the flexural strength and mode I interlaminar fracture toughness decreases by 15% and 40%, respectively, due to the presence of 3 wt% of the binder. Ballistic test was performed on E-glass/polyester composite panels using 1.1-g fragment-simulating projectiles and it was found that the binder amount has some considerable effect on the damage extension of the impacted composites. The results showed that the preforming binder has significant potential to tailor composite properties. (C) 2003 Elsevier Science Ltd. All rights reserved. |
2002 |
Akkurt, S; Ozdernir, S; Tayfur, G Genetic algorithm-artificial neural network model for the prediction of germanium recovery from zinc plant residues Journal Article TRANSACTIONS OF THE INSTITUTION OF MINING AND METALLURGY SECTION C-MINERAL PROCESSING AND EXTRACTIVE METALLURGY, 111 , pp. C129-C134, 2002, ISSN: 0371-9553. @article{ISI:000182201700003, title = {Genetic algorithm-artificial neural network model for the prediction of germanium recovery from zinc plant residues}, author = {S Akkurt and S Ozdernir and G Tayfur}, issn = {0371-9553}, year = {2002}, date = {2002-09-01}, journal = {TRANSACTIONS OF THE INSTITUTION OF MINING AND METALLURGY SECTION C-MINERAL PROCESSING AND EXTRACTIVE METALLURGY}, volume = {111}, pages = {C129-C134}, abstract = {A multi-layer, feed-forward, back-propagation learning algorithm was used as an artificial neural network (ANN) tool to predict the extraction of germanium from zinc plant residues by sulphuric acid leaching. A genetic algorithm (GA) was used for the selection of training and testing data and a GA-ANN model of the germanium leaching system was created on the basis of the training data. Testing of the model yielded good error levels (r(2) = 0.95). The model was employed to predict the response of the system to different values of the factors that affect the recovery of germanium and the results facilitate selection of the experimental conditions in which the optimum recovery will be achieved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A multi-layer, feed-forward, back-propagation learning algorithm was used as an artificial neural network (ANN) tool to predict the extraction of germanium from zinc plant residues by sulphuric acid leaching. A genetic algorithm (GA) was used for the selection of training and testing data and a GA-ANN model of the germanium leaching system was created on the basis of the training data. Testing of the model yielded good error levels (r(2) = 0.95). The model was employed to predict the response of the system to different values of the factors that affect the recovery of germanium and the results facilitate selection of the experimental conditions in which the optimum recovery will be achieved. |
2001 |
Tanoglu, M; McKnight, SH; Palmese, GR; Gillespie, JW Dynamic stress/strain response of the interphase in polymer matrix composites Journal Article POLYMER COMPOSITES, 22 (5), pp. 621-635, 2001, ISSN: 0272-8397. @article{ISI:000171840500005, title = {Dynamic stress/strain response of the interphase in polymer matrix composites}, author = {M Tanoglu and SH McKnight and GR Palmese and JW Gillespie}, doi = {10.1002/pc.10565}, issn = {0272-8397}, year = {2001}, date = {2001-10-01}, journal = {POLYMER COMPOSITES}, volume = {22}, number = {5}, pages = {621-635}, abstract = {The interphases. of various sized E-glass-fiber/epoxy-amine systems were tested at displacement rates in the range of 230 to 2450 mum/sec using a new experimental technique (dynamic micro-debonding technique). The fiber systems include unsized, epoxy-amine compatible sized, and epoxy-amine incompatible sized glass fibers. A data reduction scheme was developed to relate the force vs. displacement response obtained from the dynamic micro-debonding technique to interphase shear stress/strain response. The stress/strain curves and interphase shear modulus values were obtained from these composite systems under average shear strain rates (ASSR) in the range of 215-3278 (1/s). The results showed that the magnitude of the interphase shear modulus was sizing and strain rate dependent In all cases, the shear modulus was found to be more compliant than the bulk matrix. The two sized fiber systems exhibited the highest strain rate sensitivity, with modulus increasing about threefold over the range studied. In addition, the rate dependent behavior of the model interphase materials were determined using the dynamic mechanical analysis (DMA) technique. The model interphase materials closely resemble the interphase that forms on unsized and compatible sized fibers. Master curves relating the flexural storage modulus to strain rate were constructed based on the time-temperature superposition principle from DMA frequency sweep measurements. The DMA measured results are consistent with the dynamic micro-debonding test results, providing confidence in the test method as a reliable technique for characterizing the high strain rate properties of the interphase in composites.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The interphases. of various sized E-glass-fiber/epoxy-amine systems were tested at displacement rates in the range of 230 to 2450 mum/sec using a new experimental technique (dynamic micro-debonding technique). The fiber systems include unsized, epoxy-amine compatible sized, and epoxy-amine incompatible sized glass fibers. A data reduction scheme was developed to relate the force vs. displacement response obtained from the dynamic micro-debonding technique to interphase shear stress/strain response. The stress/strain curves and interphase shear modulus values were obtained from these composite systems under average shear strain rates (ASSR) in the range of 215-3278 (1/s). The results showed that the magnitude of the interphase shear modulus was sizing and strain rate dependent In all cases, the shear modulus was found to be more compliant than the bulk matrix. The two sized fiber systems exhibited the highest strain rate sensitivity, with modulus increasing about threefold over the range studied. In addition, the rate dependent behavior of the model interphase materials were determined using the dynamic mechanical analysis (DMA) technique. The model interphase materials closely resemble the interphase that forms on unsized and compatible sized fibers. Master curves relating the flexural storage modulus to strain rate were constructed based on the time-temperature superposition principle from DMA frequency sweep measurements. The DMA measured results are consistent with the dynamic micro-debonding test results, providing confidence in the test method as a reliable technique for characterizing the high strain rate properties of the interphase in composites. |
Tanoglu, M; Robert, S; Heider, D; McKnight, SH; Brachos, V; Gillespie, JW Effects of thermoplastic preforming binder on the properties of S2-glass fabric reinforced epoxy composites Journal Article INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES, 21 (3), pp. 187-195, 2001, ISSN: 0143-7496. @article{ISI:000169329400002, title = {Effects of thermoplastic preforming binder on the properties of S2-glass fabric reinforced epoxy composites}, author = {M Tanoglu and S Robert and D Heider and SH McKnight and V Brachos and JW Gillespie}, doi = {10.1016/S0143-7496(00)00050-6}, issn = {0143-7496}, year = {2001}, date = {2001-06-01}, journal = {INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES}, volume = {21}, number = {3}, pages = {187-195}, abstract = {The effect of a thermoplastic polyester binder on the thermophysical and mechanical properties of an S2-glass/epoxy-amine system was investigated. The purpose of the polymeric binder is to bond the individual fabric layers together during preforming prior to composite fabrication. This paper will address the significance of the binder chemistry. i.e., the compatibility of the binder with the matrix polymer. on the composite properties. The peel strength of preforms consolidated with various concentrations of binder was evaluated using the T-peel test. The highest peel resistance was obtained from preforms that have full coverage of the binder on the glass fabric. Further increase of the concentration of the binder does not change the peel strength. Scanning electron microscopy (SEM) on peel test fracture surfaces revealed mostly adhesive-type failure between binder and fiber. Double cantilever beam (DCB) and short beam shear (SBS) test results of the composite showed that the presence of about 2.6 wt% of the polyester binder reduces the Mode I interlaminar fracture toughness and apparent interlaminar shear strength of the S2-glass/SC-15 epoxy-amine system by about 60% and 25%, respectively. Moreover, the T-g of the matrix polymer within the interlaminar region decreases about 6 degreesC due to the presence of the binder. The dissolution of the polyester binder within the reacting matrix resin is limited for the standard cure cycle. (C) 2001 Elsevier Science Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The effect of a thermoplastic polyester binder on the thermophysical and mechanical properties of an S2-glass/epoxy-amine system was investigated. The purpose of the polymeric binder is to bond the individual fabric layers together during preforming prior to composite fabrication. This paper will address the significance of the binder chemistry. i.e., the compatibility of the binder with the matrix polymer. on the composite properties. The peel strength of preforms consolidated with various concentrations of binder was evaluated using the T-peel test. The highest peel resistance was obtained from preforms that have full coverage of the binder on the glass fabric. Further increase of the concentration of the binder does not change the peel strength. Scanning electron microscopy (SEM) on peel test fracture surfaces revealed mostly adhesive-type failure between binder and fiber. Double cantilever beam (DCB) and short beam shear (SBS) test results of the composite showed that the presence of about 2.6 wt% of the polyester binder reduces the Mode I interlaminar fracture toughness and apparent interlaminar shear strength of the S2-glass/SC-15 epoxy-amine system by about 60% and 25%, respectively. Moreover, the T-g of the matrix polymer within the interlaminar region decreases about 6 degreesC due to the presence of the binder. The dissolution of the polyester binder within the reacting matrix resin is limited for the standard cure cycle. (C) 2001 Elsevier Science Ltd. All rights reserved. |
Tanoglu, M; McKnight, SH; Palmese, GR; Gillespie, JW The effects of glass-fiber sizings on the strength and energy absorption of the fiber/matrix interphase under high loading rates Journal Article COMPOSITES SCIENCE AND TECHNOLOGY, 61 (2), pp. 205-220, 2001, ISSN: 0266-3538. @article{ISI:000166750300004, title = {The effects of glass-fiber sizings on the strength and energy absorption of the fiber/matrix interphase under high loading rates}, author = {M Tanoglu and SH McKnight and GR Palmese and JW Gillespie}, doi = {10.1016/S0266-3538(00)00195-0}, issn = {0266-3538}, year = {2001}, date = {2001-01-01}, journal = {COMPOSITES SCIENCE AND TECHNOLOGY}, volume = {61}, number = {2}, pages = {205-220}, abstract = {The interphases of various sized E-glass-fiber/epoxy-amine systems were tested at displacement rates in the range 230-2450 mum/s by a new experimental technique (dynamic micro-debonding technique), By this method, the rate-dependent interphase properties, apparent shear strength and absorbed energies due to debonding and frictional sliding, were quantified. The systems include unsized, epoxy-amine compatible, and epoxy-amine incompatible glass fibers. The high displacement rates that induce high-strain-rate interphase loading were obtained by using the rapid expansion capability of piezoelectric actuators (PZT). The results of dynamic micro-debonding experiments showed that the values of interphase strength and specific absorbed energies varied in a manner that is dependent on the sizing and exhibited significant sensitivity to loading rates, The unsized fibers exhibit greater frictional sliding energies that could provide better ballistic resistance, while the compatible sized fibers show higher strength values that improve the structural integrity of the polymeric composites. In addition, significantly higher amounts of energy are absorbed within the frictional sliding regime compared to debonding. By using the experimental data obtained, a case study was performed to reveal the importance of the interphase related micro damage modes on energy absorption (and therefore ballistic performance) of glass/epoxy composite armor. (C) 2001 Elsevier Science Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The interphases of various sized E-glass-fiber/epoxy-amine systems were tested at displacement rates in the range 230-2450 mum/s by a new experimental technique (dynamic micro-debonding technique), By this method, the rate-dependent interphase properties, apparent shear strength and absorbed energies due to debonding and frictional sliding, were quantified. The systems include unsized, epoxy-amine compatible, and epoxy-amine incompatible glass fibers. The high displacement rates that induce high-strain-rate interphase loading were obtained by using the rapid expansion capability of piezoelectric actuators (PZT). The results of dynamic micro-debonding experiments showed that the values of interphase strength and specific absorbed energies varied in a manner that is dependent on the sizing and exhibited significant sensitivity to loading rates, The unsized fibers exhibit greater frictional sliding energies that could provide better ballistic resistance, while the compatible sized fibers show higher strength values that improve the structural integrity of the polymeric composites. In addition, significantly higher amounts of energy are absorbed within the frictional sliding regime compared to debonding. By using the experimental data obtained, a case study was performed to reveal the importance of the interphase related micro damage modes on energy absorption (and therefore ballistic performance) of glass/epoxy composite armor. (C) 2001 Elsevier Science Ltd. All rights reserved. |
Tanoglu, M; Ziaee, S; Mcknight, SH; Palmese, GR; Gillespie, JW Investigation of properties of fiber/matrix interphase formed due to the glass fiber sizings Journal Article JOURNAL OF MATERIALS SCIENCE, 36 (12), pp. 3041-3053, 2001, ISSN: 0022-2461. @article{ISI:000169015700021, title = {Investigation of properties of fiber/matrix interphase formed due to the glass fiber sizings}, author = {M Tanoglu and S Ziaee and SH Mcknight and GR Palmese and JW Gillespie}, doi = {10.1023/A:1017979126129}, issn = {0022-2461}, year = {2001}, date = {2001-01-01}, journal = {JOURNAL OF MATERIALS SCIENCE}, volume = {36}, number = {12}, pages = {3041-3053}, abstract = {Sizings on glass fibers consist of a silane-based network that is chemically bound to the fiber and other compounds that are adsorbed onto the glass surface. Formation of interphase involves dissolution of adsorbed species and inter-diffusion of these compounds and resin monomers into the interphase region and chemical reaction of available functional groups. All these phenomena occur at the presence of the silane-based network. In this study, the effects of the silane-based network on the properties of the interphase region are investigated for an epoxy/amine resin system and compatible sized glass fibers. The composition of the sizing material bound to glass was determined using nuclear magnetic resonance (NMR) spectroscopy. Based on this information, model interphase materials were synthesized that were a blend of an epoxy/amine matrix and inclusions. The inclusions consist of an interpenetrating network of silane-based polymer and epoxy/amine thermoset that represents the interphase material formed during processing. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) techniques were used to characterize the glass transition temperature and flexural modulus of the model materials. The properties of the model interphase material were obtained using the DMA results and established micromechanics models. The results show that the glass transition temperature of the model interphase is about -5 degreesC, and its flexural storage modulus at room temperature is about 50% of that of the bulk matrix. This work has also shown that a reduction in the cross-link density of the bound network might significantly reduce the modulus within the interphase region by a factor of 5 to 8. (C) 2001 Kluwer Academic Publishers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Sizings on glass fibers consist of a silane-based network that is chemically bound to the fiber and other compounds that are adsorbed onto the glass surface. Formation of interphase involves dissolution of adsorbed species and inter-diffusion of these compounds and resin monomers into the interphase region and chemical reaction of available functional groups. All these phenomena occur at the presence of the silane-based network. In this study, the effects of the silane-based network on the properties of the interphase region are investigated for an epoxy/amine resin system and compatible sized glass fibers. The composition of the sizing material bound to glass was determined using nuclear magnetic resonance (NMR) spectroscopy. Based on this information, model interphase materials were synthesized that were a blend of an epoxy/amine matrix and inclusions. The inclusions consist of an interpenetrating network of silane-based polymer and epoxy/amine thermoset that represents the interphase material formed during processing. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) techniques were used to characterize the glass transition temperature and flexural modulus of the model materials. The properties of the model interphase material were obtained using the DMA results and established micromechanics models. The results show that the glass transition temperature of the model interphase is about -5 degreesC, and its flexural storage modulus at room temperature is about 50% of that of the bulk matrix. This work has also shown that a reduction in the cross-link density of the bound network might significantly reduce the modulus within the interphase region by a factor of 5 to 8. (C) 2001 Kluwer Academic Publishers. |
0000 |
Ç, Erdal ; Öztoprak, Funda; ğ, Faruk Ebeo M; i, I{ş}; ğ, Recep Yi; ğ, Metin Tano; Aslan, Hasan; others, Synthesis, characterization and optical properties of ZnO-CuO-Al2O3 semiconducting films on glass substrates by sol-gel technique Journal Article Usak University Journal of Material Sciences, 1 (2), pp. 147–172, 0000. @article{ccelik1synthesis, title = {Synthesis, characterization and optical properties of ZnO-CuO-Al2O3 semiconducting films on glass substrates by sol-gel technique}, author = {Erdal {Ç}elik and Funda Öztoprak and Faruk M Ebeo{ğ}lugil and I{ş}{i}l Birlik and Recep Yi{ğ}it and Metin Tano{ğ}lu and Hasan Aslan and others}, journal = {Usak University Journal of Material Sciences}, volume = {1}, number = {2}, pages = {147--172}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Project Title | Director of the Project | Start Date | Funds |
| Karbon Nanotüp (CNT) / Poliester Nanokompozitlerin Geliştirilmesi | Prof. Dr. Metin Tanoğlu | 2004 | JÜLICH, Almanya - TÜBİTAK |
| Tenzorezistörlerin Düşük Termohassasiyet Termal Katsayısı İle Geliştirilmesi | Prof. Dr. Metin Tanoğlu | 2002 | NATO |
| Havacılık uygulamaları için yapısal kompozit parçaların yenilikçi yaklaşımlar ile birleştirilme yöntemlerinin geliştirilmesi, çevresel etkilere dayanım ve mekanik performansının karakterize edilmesi | Prof. Dr. Metin Tanoğlu | 2019 | TÜBİTAK |
| Alüminyum Köpük Metal Dolu Alüminyum ve Kompozit Tüplerin Ezilme Davranışları | Prof. Dr. Mustafa Güden | 2004 | TÜBİTAK |
| Çapraz-kama haddeleme prosesinin teknik özelliklerinin Türk ve Belarus Endüstrileri için detaylandırılması | Prof. Dr. Mustafa Güden | 2010 | TÜBİTAK |
| Çok Katmanlı Malzemelerde Dalga Geçişi | Prof. Dr. Mustafa Güden | 2003 | NSF - TÜBİTAK |
| Frit Fırını Refrakterlerinin İzotermal Korozyon Testi | Prof.Dr.Sedat Akkurt | 2005 | TÜBİTAK |
| Grafen Nanolevha Takviyeli Metal Matrisli Nanokompozitlerin Geliştirilmesi | Yrd. Doç. Dr. Sinan Kandemir | 2015 | TÜBİTAK |
| Kil /EPDM Esaslı Nanokompozitlerin Geliştirilmesi | Prof. Dr. Metin Tanoğlu | 2006 | ARÇELİK A.Ş. - TÜBİTAK |
| Kompozit Malzemelerin Örgüsüz Cam / Termoplastik Hibrid Elyaflardan Geliştirilmesi | Prof. Dr. Metin Tanoğlu | 2010 | TÜBİTAK |
| Nanokompozit Malzemelerin Polimer ve Tabakalı Kil Yapılardan Geliştirilmesi ve Karakterizasyonu | Prof. Dr. Metin Tanoğlu | 2005 | TÜBİTAK |
| Patlama Etkisine Karşı Koruyucu Zırh Geliştirmesi | Prof. Dr. Metin Tanoğlu | 2008 | Milli Savunma Bakanlığı ve TÜBİTAK |
| Seramik Matriks Kompozitlerin Düşük Sıcaklıklarda Polimer Pyroliz Yöntemi İle Üretimi ve Karakterizasyonu | Prof. Dr. Metin Tanoğlu | 2002 | TÜBİTAK |
| Sic-Parçacık Takviyeli Alüminyum Köpük Metal Üretimi ve Karakterizasyonu | Prof. Dr. Mustafa Güden | 1998 | TÜBİTAK |
| Sic-Vıskırlı Aluminium Köpüklerin Hazırlanması | Prof. Dr. Mustafa Güden | 2003 | TÜBİTAK |
| Antibakteriyel Kompoze Taş Üretimi | Prof. Dr. Metin Tanoğlu | 2014 | SANTEZ |
| Gelişmiş Kemik Entegrasyonu Sağlayan Yeni Gözenekli ve Köpük Ti6Al4V Spinal Kafes İmplatların Tasarımı ve İmalatı | Prof. Dr. Mustafa Güden | 2009 | SANTEZ |
| Otomotiv Sektörüne Yönelik Kompozit Malzeme Esaslı Yaprak Yay Sistemlerinin Tasarımı ve Üretim Tekniklerinin Geliştirilmesi | Prof. Dr. Metin Tanoğlu | 2014 | SANTEZ |
| Ege Bölgesi Beylikler Dönemi Tarihi Yapılarındaki Özgün Harçların Karakterizasyonu ve Restorasyonlarda Kullanılacak Onarım Harçlarının Laboratuvarda Hazırlanması | Prof.Dr.Sedat Akkurt | 2003 | DPT |
| Fonksiyonel Dereceli Sic-Parçacık Takviyeli Alüminyum Matris Kompozit Malzemelerin Toz Metalürjisi Yöntemi İle Hazırlanması ve Statik ve Dinamik Özelliklerinin Mekanik ve Ultrasonik Yöntemlerle Ölçülmesi | Prof. Dr. Mustafa Güden | 2003 | DPT |
| Kompozit Zırh Malzemelerinin Geliştirilmesi | Prof. Dr. Metin Tanoğlu | 2003 | DPT |
| Akma ile Kalınlaşan Sıvı Zırh Sistemlerinin Geliştirilmesi | Prof. Dr. Metin Tanoğlu | 2014 | Savunma Sanayi Müsteşarlığı Projesi |
| İmplant Uygulamaları Için Ti Köpük Malzemelerin Hazırlanması | Prof. Dr. Mustafa Güden | 2003 | HİPOKRAT |
| Seramik Vitrifiye Ürünlerin Yüksek Basınçlı Dökümü Için Gözenekli Malzemelerin Geliştirilmesi ve Karakterizasyonu | Prof. Dr. Metin Tanoğlu | 2001 | EGE VİTRİFİYE A.Ş |
| Çoklu Alüminyum Kapalı Hücreli Köpük Dolu Alüminyum ve Polimerik Kompozit Tüplerin Ezilme Davranışlarının Belirlenmesi | Prof. Dr. Mustafa Güden | 2003 | İYTE-BAP |
| FP Aluminium Uzun Fiber Takviyeli Magnesium Kompozitlerin Deformasyon Hızına Bağlı Mekanik Davranışları | Prof. Dr. Mustafa Güden | 2003 | İYTE-BAP |
| Hafif, Düşük Maliyetli Polimer Esaslı Kompozit Malzemelerin Üretim Teknolojilerinin Yerleştirilmesi ve Savunma Sanayi Ne Yönelik Kompozit Zırh Malzemelerin Geliştirilmesi | Prof. Dr. Metin Tanoğlu | 2001 | İYTE-BAP |
| Jeotermal Uygulamalar İçin Polimerik Kompozit Boru Malzeme Mikroyapısısnın Malzeme Dayanım, Mekanik ve Termal Özelliklerine Etkisi | Prof. Dr. Metin Tanoğlu | 2002 | İYTE-BAP |
| Kölemanit Ilkavesiyle Kaolen Ve Kalsitten Anortit Seramikleri Sentezlenmesi ve Sinterlenmesi | Prof.Dr.Sedat Akkurt | 2004 | İYTE-BAP |
| Korozyona Uğramış Manyezit-Bazlı Çimento Fırını Refrakterlerin Mikroyapısal Karakterizasyon | Prof.Dr.Sedat Akkurt | 2001 | İYTE-BAP |
| Krom Manyezit Çimento Fırını Refrakterlerinde Bulunan Demirce Zengin Halkaların İncelenmesi | Prof.Dr.Sedat Akkurt | 2002 | İYTE-BAP |
| Nanokompozit malzemelerin geliştirilmesi ve karakterizasyonu | Prof. Dr. Metin Tanoğlu | 2003 | İYTE-BAP |
| Sinterlenmiş Yüksek Saflıktaki Alüminanın Bof Curuflarıyla Korozyonunun Laboratuvar İncelemesi | Prof.Dr.Sedat Akkurt | 2001 | İYTE-BAP |
| Spinel ve Alüminanın Düşük Sıcaklıkta Üretiminde Mekanokimyasal Sentezin Kullanılması | Prof.Dr.Sedat Akkurt | 2002 | İYTE-BAP |
| Titanyum Esaslı Açık Hücreli Köpük Metal Üretim Proses Parametrelerinin ve Mekanik Özelliklerinin Belirlenmesi | Prof. Dr. Mustafa Güden | 2004 | İYTE-BAP |
| Yüksek Balistik Dayanımlı Kompozit Hafif Zırh Malzemelerinin Geliştirilmesi | Prof. Dr. Metin Tanoğlu | 2002 | İYTE-BAP |
