The crystallization behavior and kinetics of CaO-MgO-Al2O3 SiO2（CMAS） glass with the Fe2O3 content ranging from zero to 5%were investigated by differential scanning calorimetry（DSC）.The structure and phase analyse...The crystallization behavior and kinetics of CaO-MgO-Al2O3 SiO2（CMAS） glass with the Fe2O3 content ranging from zero to 5%were investigated by differential scanning calorimetry（DSC）.The structure and phase analyses were made by Fourier transform infrared spectroscopy（FT-IR） and X-ray diffraction（XRD）.The experiment results show that the endothermic peak temperature about 760℃ is associated with transition and the exothermic peak temperature about 1000℃ is associated with crystallization.The crystallization peak temperature decreases with increasing the Fe203 content.The crystallization mechanism is changed from two-dimensional crystallization to one-dimensional growth,and the intensity of diopside peaks becomes stronger gradually.There is a saltation for the crystallization temperature with the addition of 0.5%Fe2O3 due to the decomposition of Fe2O3.Si-O-Si,O-Si-O and T-O-T（T=Si,Fe,Al） linkages are observed in Fe2O3-CaO-MgO-Al2O3-SiO2 glass.展开更多
A series of asymmetric cordierite ceramics with hierarchical porous structure were prepared and characterized.The macroporous support was obtained from natural raw materials (bauxite,silica sand,kaolinite,talc,and alu...A series of asymmetric cordierite ceramics with hierarchical porous structure were prepared and characterized.The macroporous support was obtained from natural raw materials (bauxite,silica sand,kaolinite,talc,and alumina) via ceramic technology.The prepared ceramic discs were characterized by a narrow pore size distribution.The average pore size was about 9.5 μm,and the open porosity was estimated to be 30％.Coating the discs with micro/mesoporous cordierite layer was performed using the sol-gel approach.Three-component sols were obtained from organic or inorganic precursors.Corresponding gels were calcined at 1200 ℃ to form the cordierite structure.The nature of precursor was found to affect the pore volume distribution.Narrow pore volume distribution was observed when organic precursors were used.Another key factor to control the parameters of final material was the drying condition.Supercritical drying of the gels has allowed us to increase the surface area in two orders of magnitude comparing with conventional drying procedure.展开更多
基金Projects(51264023,51364020,U1202271)supported by the National Natural Science Foundation of ChinaProject(IRT1250)supported by the Program for Innovative Research Team in University of Ministry of Education of ChinaProject(2014HA003)supported by the Science and Technology Leading Talent of Yunnan Province,China
文摘The crystallization behavior and kinetics of CaO-MgO-Al2O3 SiO2（CMAS） glass with the Fe2O3 content ranging from zero to 5%were investigated by differential scanning calorimetry（DSC）.The structure and phase analyses were made by Fourier transform infrared spectroscopy（FT-IR） and X-ray diffraction（XRD）.The experiment results show that the endothermic peak temperature about 760℃ is associated with transition and the exothermic peak temperature about 1000℃ is associated with crystallization.The crystallization peak temperature decreases with increasing the Fe203 content.The crystallization mechanism is changed from two-dimensional crystallization to one-dimensional growth,and the intensity of diopside peaks becomes stronger gradually.There is a saltation for the crystallization temperature with the addition of 0.5%Fe2O3 due to the decomposition of Fe2O3.Si-O-Si,O-Si-O and T-O-T（T=Si,Fe,Al） linkages are observed in Fe2O3-CaO-MgO-Al2O3-SiO2 glass.
文摘A series of asymmetric cordierite ceramics with hierarchical porous structure were prepared and characterized.The macroporous support was obtained from natural raw materials (bauxite,silica sand,kaolinite,talc,and alumina) via ceramic technology.The prepared ceramic discs were characterized by a narrow pore size distribution.The average pore size was about 9.5 μm,and the open porosity was estimated to be 30％.Coating the discs with micro/mesoporous cordierite layer was performed using the sol-gel approach.Three-component sols were obtained from organic or inorganic precursors.Corresponding gels were calcined at 1200 ℃ to form the cordierite structure.The nature of precursor was found to affect the pore volume distribution.Narrow pore volume distribution was observed when organic precursors were used.Another key factor to control the parameters of final material was the drying condition.Supercritical drying of the gels has allowed us to increase the surface area in two orders of magnitude comparing with conventional drying procedure.
