Sol-gel Synthesis of Macroporous YAG from Ionic Precursors via Phase Separation Route
Sol-gel Synthesis of Macroporous YAG from Ionic Precursors via Phase Separation Route
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DOI：
10.2109/jcersj2.115.925
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发表时间：
2007
影响因子：
1.1
通讯作者：
Yasuaki Tokudome;K. Fujita;K. Nakanishi;K. Kanamori;K. Miura;K. Hirao;T. Hanada
中科院分区：
文献类型：
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作者：
Yasuaki Tokudome;K. Fujita;K. Nakanishi;K. Kanamori;K. Miura;K. Hirao;T. Hanada
在甲酰胺（FA）和聚乙烯吡咯烷酮（PVP）存在下，采用溶胶-凝胶相分离法制备了由离子前驱体衍生的整体大孔二氧化钛（TiO2）。FA的加入促进了凝胶化，PVP的加入则增强了聚合诱导的相分离。选择合适的起始成分，可以生产出大尺寸的共连续大孔TiO2单体，并控制大孔的大小。所得的干燥凝胶是无定形的，而锐钛矿和金红石相分别在500°C和900°C析出，而不破坏大孔形态。氮气吸附-解吸测试表明，干燥后的凝胶具有中等孔径约3 nm的介观结构，BET表面积为228 m2/g，而在600°C下煅烧的凝胶为15 nm和73 m2/g。
Monolithic macroporous titanium dioxide (TiO2) derived from ionic precursors has been successfully prepared via the sol–gel route accompanied by phase separation in the presence of formamide (FA) and poly(vinylpyrrolidone) (PVP). The addition of FA promotes the gelation, whereas PVP enhances the polymerization-induced phase separation. Appropriate choice of the starting compositions allows the production of cocontinuous macroporous TiO2 monoliths in large dimensions, and controls the size of macropores. The resultant dried gel is amorphous, whereas anatase and rutile phases are precipitated at 500 and 900 °C respectively, without spoiling the macroporous morphology. Nitrogen adsorption–desorption measurements revealed that the dried gels exhibits mesostructure with a median pore size of about 3 nm and BET surface area of 228 m2/g, whereas 15 nm and 73 m2/g for the gels calcined at 600 °C.