Solvothermal removal of the organic template from L3 (“sponge- templated silica monoliths

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• 作者：Daniel M. Dabbs ; Norbert Mulders and Ilhan A. Aksay
• 关键词：nanostructured ceramics ; high surface area silica ; extraction ; supercritical solvent ; synthesis
• 刊名：Journal of Nanoparticle Research
• 出版年：2006
• 出版时间：October, 2006
• 年：2006
• 卷：8
• 期：5
• 页码：603-614
• 全文大小：390 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Nanotechnology
  Inorganic Chemistry
  Characterization and Evaluation Materials
  Physical Chemistry
  Applied Optics, Optoelectronics and Optical Devices
  
• 出版者：Springer Netherlands
• ISSN：1572-896X

文摘

We compare the methods of continuous solvent (Soxhlet) and supercritical solvent extractions for the removal of the organic template from nanostructured silica monoliths. Our monoliths are formed by templating the L ₃ liquid crystal phase of cetylpyridinium chloride in aqueous solutions with tetramethoxy silane. The monoliths that result from both Soxhlet and supercritical extraction methods are mechanically robust, optically clear, and free of cracks. The Soxhlet method compares favorably with supercritical solvent extraction in that equivalent L ₃-templated silica can be synthesized without the use of specialized reactor hardware or higher temperatures and high pressures, while avoiding noxious byproducts. The comparative effectiveness of various solvents in the Soxhlet process is related to the Hildebrand solubility parameter, determined by the effective surface area of the extracted silica.