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Novel organic-inorganic hybrid and nano-structured materials.

机译：新型有机-无机杂化和纳米结构材料。

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摘要

Organic polymers, i.e. polymethacrylates and polystyrene, and inorganic silica were successfully integrated covalently into one body, i.e. hybrid materials, at molecular level in a continuum ranging from pure polymer to pure silica via the sol-gel process. The synthetic conditions have been systematically studied and optimized. A fast and convenient method for the synthesis of polymethacrylate-silica hybrids with significantly low volume-shrinkages has been developed to address the intrinsic problems of the sol-gel process, i.e. large volume shrinkage and long drying times.; The relationship of properties of the hybrids with the structures and organic-inorganic compositions have been established. The density, hardness and thermal stability increase with the silica content. Atomic force microscopy study of the morphology shows that the transparent hybrid materials, in which the polymer chains have a strong and intimate interaction with the silica matrix, have significantly different surface features from a translucent control sample. The compressive behavior of the hybrid materials is completely different from that of traditional composites. Toughness of the hybrid materials can be maximized and the strength can be dramatically increased by varying the silica content. Possible mechanisms for the formation of hybrid materials are proposed. Potential applications of the hybrid materials as dental fillers and cation exchangers were investigated.; Amorphous silica was functionalized by doping with optically active compounds such as scD-glucose, diphenyl tartaric acid and maltose. The resultant nano-structured materials show excellent optical transparency to visible light. Optical rotation of the materials in the solid state was demonstrated quantitatively to be the same as that in solution. The specific rotation can be calculated directly according to Biot's equation. A non-surfactant templating approach has been developed for the preparation of mesoporous silica by removing the organic compounds (i.e. template) through solvent extraction. The mesoporous nature of the materials is evidenced by the large BET surface area and pore volumes, the controllable pore sizes of {dollar}{lcub}sim{rcub}2{dollar} to 6 nm and their narrow distributions, the powder X-ray diffraction patterns, and transmission electron microscopy images. The pore size can be tuned simply by adjusting the template concentration. This non-surfactant structure-directing pathway possesses many advantages over the known surfactant approaches.
机译：有机分子聚合物，即聚甲基丙烯酸酯和聚苯乙烯，以及无机二氧化硅，通过溶胶-凝胶法成功地以分子水平共价地整合到一个单体即杂化材料中，其分子水平在从纯聚合物到纯二氧化硅的连续范围内。对合成条件进行了系统的研究和优化。为了解决溶胶-凝胶工艺的固有问题，即大体积收缩和长干燥时间，已经开发了一种快速方便的合成方法，该方法具有很低的体积收缩率。已经建立了杂种的特性与结构和有机-无机组成的关系。密度，硬度和热稳定性随二氧化硅含量的增加而增加。原子力显微镜对形态的研究表明，透明的杂化材料中的聚合物链与二氧化硅基质具有牢固而紧密的相互作用，其表面特征与半透明的对照样品有很大不同。杂化材料的压缩行为与传统复合材料完全不同。通过改变二氧化硅含量，可以使杂化材料的韧性最大化，并且可以显着提高强度。提出了形成混合材料的可能机制。研究了杂化材料作为牙科填充剂和阳离子交换剂的潜在应用。通过掺杂光学活性化合物（例如scD-葡萄糖，二苯基酒石酸和麦芽糖）将无定形二氧化硅功能化。所得的纳米结构材料对可见光显示出优异的光学透明性。定量证明了固态材料的旋光性与溶液中的旋光性相同。比旋光度可以根据Biot方程直接计算。已经开发了一种非表面活性剂的模板方法，该方法用于通过溶剂萃取除去有机化合物（即模板）来制备中孔二氧化硅。材料的介孔性质由较大的BET表面积和孔体积，{dollar} {lcub} sim {rcub} 2 {dollar}的可控制孔径（至6 nm）及其窄分布，粉末X射线证明。衍射图和透射电子显微镜图像。可以通过调节模板浓度简单地调节孔径。与已知的表面活性剂方法相比，这种非表面活性剂的结构导向途径具有许多优点。

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  • 作者

    Jin, Danliang.;

  • 作者单位

    Drexel University.;

  • 授予单位 Drexel University.;
  • 学科 Chemistry Polymer.; Engineering Materials Science.; Physics Optics.
  • 学位 Ph.D.
  • 年度 1997
  • 页码 552 p.
  • 总页数 552
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 高分子化学（高聚物）;工程材料学;光学;
  • 关键词

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