Functionalization of large-pore mesoporous silicas with organosilanes by direct synthesis
Functionalization of large-pore mesoporous silicas with organosilanes by direct synthesis
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DOI：
10.1016/j.micromeso.2004.04.015
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发表时间：
2004-07-08
影响因子：
5.2
通讯作者：
Qiao, SZ
中科院分区：
文献类型：
--
作者：
Chong, ASM;Zhao, XS;Qiao, SZ
多孔固体的功能化在酶固定化等许多技术方面起着重要的作用。在本研究中，在非离子三嵌段共聚物Pluronic P 123存在下，通过正硅酸乙酯（TEOS）与有机硅烷3-氨丙基三乙氧基硅烷（APTES）、3-巯丙基甲氧基硅烷（MPTMS）、苯基三甲氧基硅烷（PTMS）、乙烯基三乙氧基硅烷（VTES）和4-（三乙氧基硅基）丁腈（TSBN）在酸性条件下共缩合，合成了具有P6 mm对称性的功能化大孔介孔材料。通过改变有机硅烷与TEOS的摩尔比，系统地研究了初始合成混合物中存在的有机硅烷对所得材料的介观结构性质的影响。固态核磁共振（NMR），X-射线光电子能谱（XPS），热重分析（TGA），和元素分析数据表明，在孔表面和固体基质内的官能团的存在下。氮吸附，小角X-射线散射（SAXS），和透射电子显微镜（TEM）的结果表明，不同程度的无序的介观结构时，纳入的官能团，这取决于类型和量的有机硅烷存在于初始合成混合物。在所研究的有机硅烷中，它们对介观结构形成的破坏作用遵循VTES < TSBN < PTMS，相当于MPTMS < APTES。这种不同的效果被解释为在酸性合成条件下的不同行为和空间的分子大小和形状，这对P123与硅酸盐物种的相互作用和P123模板的胶束化有直接的影响。(C)2004年爱思唯尔公司All rights reserved.
Functionalization of porous solids plays an important role in many technical aspects such as enzyme immobilization. In this study, functionalized large-pore mesoporous materials with a P6mm symmetry were synthesized by co-condensation of tetraethyl orthosilicate (TEOS) and organosilanes 3-aminopropyltriethoxysilane (APTES), 3-mercaptopropylmethoxysilane (MPTMS), phenyltrimethoxysilane (PTMS), vinyltriethoxysilane (VTES), and 4-(triethoxysilyl)butyronitrile (TSBN) in the presence of nonionic triblock co-polymer Pluronic P 123 under acidic conditions. The effect of the organosilanes present in the initial synthesis mixtures on the mesostructural properties of the resultant materials was systematically studied by varying the molar ratios of organosilane to TEOS. Solid-state nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and elemental analysis data demonstrated the presence of the functional groups both on the pore surface and inside the solid matrixes. Nitrogen adsorption, small-angle X-ray scattering (SAXS), and transmission electron microscopy (TEM) results showed different levels of disorder of the mesostructures upon incorporation of the functional groups, which are dependent upon the type and amount of the organosilanes present in the initial synthesis mixtures. Among the organosilanes studied, their disruptive effects on the formation of the mesostructure follow VTES < TSBN < PTMS equivalent to MPTMS < APTES. Such different effects are interpreted in terms of their different behaviors under acidic synthetic conditions and steric molecular sizes and shapes, which have direct impact on interactions of P123 with silicate species and on micellation of P123 template. (C) 2004 Elsevier Inc. All rights reserved.