Synthesis of Silica-Based Nanostructured Hybrid via Supramolecular Chemical Approaches

通过设计的两亲性硅基前驱体的自组装，得到了各种有序杂化材料。烷氧基硅烷和氯硅烷与共价连接的疏水有机尾巴一起被水解，形成含有硅醇基的两亲性分子，从而形成层状(片状)结构。具有烷基链和大的低聚硅氧烷头部的分子的设计导致了由圆柱形组装组成的中间相的形成，提供了一条直接获得有序多孔二氧化硅的途径。我们还报道了利用1-炔基三甲氧基硅烷合成具有层状和虫孔状介孔结构的硅基杂化材料。在TMOS存在下制备的具有虫孔状介孔结构的杂化材料，通过化学处理或焙烧的方法转化为介孔二氧化硅。此外，我们还展示了由具有亚甲基、乙烯和苯亚甲基桥联的双(三氯硅烷)烷氧基衍生物形成的新型层状材料。另一方面，我们发现了一类新的笼状低聚物，它们是在四甲基氢氧化铵存在下，通过亚甲基桥联双烷氧基硅烷前驱体的水解和缩聚选择性地形成的。

A variety of ordered hybrid materials have been obtained by self-assembly of designed amphiphilic silicon-based precursors. Alkoxysilanes and chlorosilanes with covalently attached hydrophobic organic tails are hydrolyzed to form amphiphilic molecules containing silanol groups, leading to the formation of layered (lamellar) structures. The design of molecules having alkyl chains and large oligosiloxane heads led to the formation of mesophases consisting of cylindrical assemblies, providing a direct pathway to ordered porous silica. We also reported the synthesis of silica-based hybrids with lamellar and wormhole-like mesostructures using of 1-alkynyltrimethoxysilanes. The hybrids with wormhole-like mesostructures, prepared in the presence of TMOS, were converted into mesoporous silica either by chemical treatment or by calcination. Furthermore, we have demonstrated the formation of novel layered materials from alkoxy-derivatives of bis(trichlorosilanes) having methylene, ethylene, and phenylene bridges. On the other hand, we discovered a new class of cage-like oligomers which were selectively formed by hydrolysis and polycondensation of a methylene-bridged bistrialkoxysilane precursor in the presence of tetramethyl-ammonium hydroxide.