The porous ceramics based on Al2O3-TiO2/ZrO2-SiO2 from particle-stabilized wet foam by direct foaming were discussed.The initial Al2O3-TiO2 suspension was prepared by adding TiO2 suspension to partially hydrophobized ...The porous ceramics based on Al2O3-TiO2/ZrO2-SiO2 from particle-stabilized wet foam by direct foaming were discussed.The initial Al2O3-TiO2 suspension was prepared by adding TiO2 suspension to partially hydrophobized colloidal Al2O3 suspension with equimolar amount,to form Al2TiO5 on sintering.The secondary ZrO2-SiO2 suspension was prepared using the equimolar composition,and to obtain ZrSiO4,ZrTiO4,and mullite phases in the sintered samples,the secondary suspension was blended into the initial suspension at 0,10,20,30,and 50 vol％.The wet foam exhibited an air content up to 87％,Laplace pressure from 1.38 to 2.23 mPa,and higher adsorption free energy at the interface of approximately 5.8×108 to 7.5×108J resulting an outstanding foam stability of 87％.The final suspension was foamed,and the wet foam was sintered from 1400 to 1600 ℃ for 1 h.The porous ceramics with pore size from 150 to 400 μm on average were obtained.The phase identification was accomplished using X-ray diffraction (XRD),differential thermal analysis (DTA),and thermogravimetric analysis (TGA),and microstructural analysis was performed using field emission scanning electron microscopy (FESEM).展开更多
Carbon nanotubes(CNTs)have attracted intensive interests of researchers for a long time due to their fascinating physical and chemical properties promising for various potential applications,including advanced ceramic...Carbon nanotubes(CNTs)have attracted intensive interests of researchers for a long time due to their fascinating physical and chemical properties promising for various potential applications,including advanced ceramics,nanoelectronic devices,nanoscale sensors,solar cells,battery electrode,field emitters,etc..This review summarized the synthetic methods of CNTs,with an emphasis on the chemical vapor deposition(CVD)method,especially catalytic CVD.Although there still are some challenges in the way,with the development of the technology,a hope for widespread applications always exists.展开更多
文摘The porous ceramics based on Al2O3-TiO2/ZrO2-SiO2 from particle-stabilized wet foam by direct foaming were discussed.The initial Al2O3-TiO2 suspension was prepared by adding TiO2 suspension to partially hydrophobized colloidal Al2O3 suspension with equimolar amount,to form Al2TiO5 on sintering.The secondary ZrO2-SiO2 suspension was prepared using the equimolar composition,and to obtain ZrSiO4,ZrTiO4,and mullite phases in the sintered samples,the secondary suspension was blended into the initial suspension at 0,10,20,30,and 50 vol％.The wet foam exhibited an air content up to 87％,Laplace pressure from 1.38 to 2.23 mPa,and higher adsorption free energy at the interface of approximately 5.8×108 to 7.5×108J resulting an outstanding foam stability of 87％.The final suspension was foamed,and the wet foam was sintered from 1400 to 1600 ℃ for 1 h.The porous ceramics with pore size from 150 to 400 μm on average were obtained.The phase identification was accomplished using X-ray diffraction (XRD),differential thermal analysis (DTA),and thermogravimetric analysis (TGA),and microstructural analysis was performed using field emission scanning electron microscopy (FESEM).
基金This research was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MEST)by a grant from the 2012 Fundamental R&D Program of Hanseo University,Korea.
文摘Carbon nanotubes(CNTs)have attracted intensive interests of researchers for a long time due to their fascinating physical and chemical properties promising for various potential applications,including advanced ceramics,nanoelectronic devices,nanoscale sensors,solar cells,battery electrode,field emitters,etc..This review summarized the synthetic methods of CNTs,with an emphasis on the chemical vapor deposition(CVD)method,especially catalytic CVD.Although there still are some challenges in the way,with the development of the technology,a hope for widespread applications always exists.
