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    National Tsing Hua University Institutional Repository > 理學院 > 化學系 > 期刊論文 >  Continuous formation of supported cubic and hexagonal mesoporous films by sol gel dip-coating

    Please use this identifier to cite or link to this item: http://nthur.lib.nthu.edu.tw/dspace/handle/987654321/57050

    Title: Continuous formation of supported cubic and hexagonal mesoporous films by sol gel dip-coating
    Authors: Lu YF;Ganguli R;Drewien CA;Anderson MT;Brinker CJ;Gong WL;Guo YX;Soyez H;Dunn B;Huang MH;Zink JI
    教師: 黃暄益
    Date: 1997
    Publisher: Nature Publishing Group
    Relation: Nature -London,Nature Publishing Group,Volume: 389,Issue: 6649,Pages: 364-368,Published: SEP 25 1997
    Keywords: SILICA
    Abstract: Thin films of surfactant-templated mesoporous materials(1,2) could find applications in membrane-based separations, selective catalysis and sensors. Above the critical micelle concentration of a bulk silica-surfactant solution, films of mesophases with hexagonally packed one-dimensional channels can be formed at solid-liquid and liquid-vapour interfaces(3-5). But this process is slow and the supported films(3,5) are granular and with the pore channels oriented parallel to the substrate surface, so that transport across the films is not facilitated by the pores. Ogawa(6,7) has reported a rapid spin-coating procedure for making transparent mesoporous films, but their formation mechanism, microstructure and pore accessibility have not been elucidated. Here we report a sol-gel-based dip-coating method for the rapid synthesis of continuous mesoporous thin films on a solid substrate. The influence of the substrate generates film mesostructures that have no bulk counterparts, such as composites with incipient liquid-crystalline order of the surfactant-silica phase. We are also able to form mesoporous films of the cubic phase, in which the pores are connected in a three-dimensional network that guarantees their accessibility from the film surface. We demonstrate and quantify this accessibility using a surface-acoustic-wave nitrogen-adsorption technique. We use fluorescence depolarization to monitor the evolution of the mesophase in situ, and see a progression through a sequence of lamellar to cubic to hexagonal structures that has not previously been reported.
    URI: http://www.nature.com/
    Appears in Collections:[化學系] 期刊論文

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