| Summary: | 碩士 === 國立臺灣大學 === 化學工程學研究所 === 90 === Fully crystallized tin oxide of high surface area and nanopore-size uniformity was obtained by adopting a novel process which including Liquid-Crystal-Template, Sol-Gel method and HMDS used. Tin oxide hydrous sol was first synthesized and peptized via the conventional sol-gel process and then mixed with cetyltrimethylammonium bromide (CTAB). After heating at 300oC to completely burn off the organics, the resulted crystalline tin oxide powder exhibited a surface area of 303 m2/g and an average pore size of 2.9 nm. When adding HMDS in the synthetic process, crystalline tin oxide powder owns a surface area of 352 m2/g and a hexagonal mesoporous structure with 2.4 nm and 1st geometric standard deviation of 2.8 at 300 oC calcinated. In order to maintain the nanoporous structure of tin oxide after high temperature calcinations, the hydroxyl group on the surface of hydrous tin oxide gel is replaced by methyl siloxyl group from Hexamethyldisilazane (HMDS) to inhibit crystal growth effectively before calcinations. As a result of calcination at 500 oC, the powder retained a surface area of 220 m2/g. In our research, we also analyzed and discussed the fine structure and chemical composition changing of tin oxide in calcination processes.
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