Spontaneous Formation and Characterization of Silica Mesoporous Crystal Spheres with Reverse Multiply Twinned Polyhedral Hollows

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• 作者：Lu Han ; Ping Xiong ; Jingfeng Bai ; Shunai Che
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：April 27, 2011
• 年：2011
• 卷：133
• 期：16
• 页码：6106-6109
• 全文大小：850K
• 年卷期：v.133,no.16(April 27, 2011)
• ISSN：1520-5126

文摘

A crystal is an object with translational symmetry. Basic research into and production of new materials necessitates the preparation of crystals of a particular morphology and with well-defined crystal defects. In this work, we found novel silica mesoporous crystal spheres with polyhedral hollows (icosahedral, such as those observed for proteins of virus capsids, decahedral, Wulff polyhedral, etc.) formed by the reverse multiply twinned bicontinuous double diamond mesostructure. Vesicles with a low-curvature lamellar structure were first formed by the self-assembly of amphiphilic carboxylic acid molecules in the presence of a nonionic surfactant and then underwent a structural transformation process that gave a reverse multiply twinned mesoporous shell while maintaining the hollow shape. These polyhedral hollow crystals showed an enhanced contrast of backscattering signatures relative to the incident acoustic signals and thus could be used as a potential contrast agent in medical ultrasonography with drug loadings in the mesopores.