Wang Xueguang, Lin Kyle S K, Chan Jerry C C, Cheng Soofin
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
J Phys Chem B. 2005 Feb 10;109(5):1763-9. doi: 10.1021/jp045798d.
SBA-15 mesoporous silica has been functionalized with aminopropyl groups through a simple co-condensation approach of tetraethyl orthosilicate (TEOS) and (3-aminopropyl)triethoxysilane (APTES) using amphiphilic block copolymers under acidic conditions. The organic-modified SBA-15 materials have hexagonal crystallographic order, pore diameter up to 60 A, and the content of aminopropyl groups up to 2.3 mmol g(-1). The influences of TEOS prehydrolysis period and APTES concentration on the crystallographic order, pore size, surface area, and pore volume were examined. TEOS prehydrolysis prior to the addition of APTES was found essential to obtain well-ordered mesoporous materials with amino functionality. The amount of APTES incorporated in the silica framework increased with the APTES concentration in the synthesis gel, while the ordering of the mesoporous structure gradually decreased. Analysis with TG, IR, and solid state NMR spectra demonstrated that the aminopropyl groups incorporated in SBA-15 were not decomposed during the preparation procedure and the surfactant P123 was fully removed through ethanol extraction. The modified SBA-15 was an excellent base catalyst in Knoevenagel and Michael addition reactions.
通过在酸性条件下使用两亲性嵌段共聚物，采用正硅酸乙酯（TEOS）和（3-氨丙基）三乙氧基硅烷（APTES）的简单共缩聚方法，对SBA-15介孔二氧化硅进行了氨丙基官能化。有机改性的SBA-15材料具有六方晶体学有序结构，孔径可达60 Å，氨丙基含量可达2.3 mmol g⁻¹。研究了TEOS预水解时间和APTES浓度对晶体学有序性、孔径、表面积和孔体积的影响。发现APTES添加之前进行TEOS预水解对于获得具有氨基官能团的有序介孔材料至关重要。二氧化硅骨架中掺入的APTES量随合成凝胶中APTES浓度的增加而增加，而介孔结构的有序性逐渐降低。通过热重分析（TG）、红外光谱（IR）和固体核磁共振光谱（NMR）分析表明，掺入SBA-15中的氨丙基在制备过程中未分解，并且通过乙醇萃取完全除去了表面活性剂P123。改性后的SBA-15在Knoevenagel反应和Michael加成反应中是一种优异的碱催化剂。
