首页> 外文OA文献 >Characterization and fabrication of nanoporous materials by template-directed sol-gel methods
【2h】

Characterization and fabrication of nanoporous materials by template-directed sol-gel methods

机译:通过模板定向溶胶 - 凝胶方法表征和制造纳米多孔材料

摘要

This research project focussed on developing synthetic strategies to fabricate a variety of nanoporous materials ranging the full range of pore sizes from micro to macro using template assisted sol-gel routes. Both colloidal crystals and surfactant self assemblies were employed as templates. Initial studies focussed on the fabrication of macroporous titano/alumino and tinsilicate materials by dip infiltrating colloidal crystal templates with sol-gel mixtures. The sols were prehydrolysed in order to ensure atomic scale homogeneity of the final material. These materials were subsequently characterised using SEM to observe the macrostructure whilst XRD, EDX, NMR and iR were used to characterise the thermal stability and chemical homogeneity. The work reports materials with metal:silicon atomic ratios for macroporous titanosilicates and aluminosilicates that are far in excess of those previously reported in the literature. Following this research was focused on the production of hierarchically ordered meso/macro silica materials by dip coating a preformed colloidal crystal into a sol-gel solution which contained surfactants. This technique combines principles of colloidal crystal templating and liquid crystal templating and by varying the surfactant it was possible to obtain mesoporous pore walls with both ordered and wormhole pore morphologies. The materials were characterised with both SEM, TEM and Nitrogen sorption and exhibited surface areas in excess of 500 m2 g-1. It was further shown that the mesopore size could be tuned by choosing different surfactants and mesopore sizes ranging from 2-7 nm were produced. Finally, the synthetic procedures developed to produce meso/macro silica were used to produce meso/macro titania and zirconia by extending the method to incorporate different metal alkoxides precursors. These materials were once again characterised by SEM, TEM and nitrogen sorption and it was shown meso/macro titania and zirconia could be easily fabricated using this simple approach. It was also shown that the ordering in these materials was more sensitive to the chosen surfactant with only larger tri-block copolymer surfactants yielding stable mesostructures.
机译:该研究项目专注于开发合成策略,以利用模板辅助溶胶-凝胶途径制备各种纳米孔径的材料,其孔径范围从微观到宏观。胶体晶体和表面活性剂自组装都被用作模板。最初的研究集中在通过用溶胶-凝胶混合物浸入胶体晶体模板来制造大孔钛/铝和硅酸锡材料。溶胶被预水解以确保最终材料的原子尺度均匀性。随后使用SEM对这些材料进行表征,以观察其宏观结构,同时使用XRD,EDX,NMR和iR表征热稳定性和化学均匀性。该工作报告的大孔钛硅酸盐和铝硅酸盐的金属原子比为硅原子比,远远超过了先前文献中报道的那些。这项研究的重点是通过将预先形成的胶体晶体浸涂到含有表面活性剂的溶胶-凝胶溶液中,从而生产分级有序的介孔/宏观二氧化硅材料。该技术结合了胶体晶体模板化和液晶模板化的原理,并且通过改变表面活性剂,可以获得具有有序和虫孔形貌的中孔壁。该材料通过SEM,TEM和氮吸附进行了表征,并显示出超过500 m2 g-1的表面积。进一步表明,可以通过选择不同的表面活性剂来调节中孔尺寸,并且产生范围为2-7nm的中孔尺寸。最后,通过扩展方法以掺入不同的金属醇盐前体,用于生产内消旋/宏观二氧化硅的合成程序可用于生产内消旋/宏观氧化钛和氧化锆。这些材料再次通过SEM,TEM和氮吸附进行了表征,结果表明,使用这种简单方法可以轻松制造中观/宏观二氧化钛和氧化锆。还显示出这些材料中的排序对所选表面活性剂更敏感,仅较大的三嵌段共聚物表面活性剂产生稳定的介孔结构。

著录项

  • 作者

    Hant Steven Michael;

  • 作者单位
  • 年度 2008
  • 总页数
  • 原文格式 PDF
  • 正文语种 English
  • 中图分类

相似文献

  • 外文文献
  • 中文文献
  • 专利

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号