| Summary: | 碩士 === 國立中央大學 === 化學研究所 === 97 === The thesis is divided into three parts. Studies on functionalization of mesoporous materials. In part one, the mesoporous silica SBA-1 (cubic Pm3n symmetry) functionalized with phenyl groups were synthesized via co-condensation of 1,4-bis(triethoxysilyl)benzene (BTEB) and tetraethoxysilane (TEOS) under acidic conditions using cetyltriethylammonium bromide (CTEABr) as a structure-directing agent. By optimizing the synthesis composition, the resulting materials exhibited much higher surface areas (up to 1210 m2/g) and larger pore volumes (up to 0.64 cm3/g) as compared to the previous analogue, which only exhibited a surface area of 381 cm2/g and a pore volume of 0.11 cm3/g. Two dimensional (2D) 29Si{1H} heteronuclear correlation (HETCOR) NMR spectra, acquired as a function of contact time, provided direct spectroscopic evidence that a single mesophase with various Q (from TEOS) and T silicon species (from BTEB) located randomly within the pore walls via co-condensation of BTEB and TEOS at a molecular level. Such information is often not achievable by other characterization techniques
In part two, well-ordered cubic mesoporous silica SBA-1 functionalized with amino functional groups have been synthesized via co-condensation of tetraethoxysilane (TEOS), (3-aminopropyl)trimethoxysilane (APTMS) templated by cetyltriethylammonium bromide (CTEABr), under strongly acidic condition by using chlorosulfonic acid as an acidic medium. The materials thus obtained were characterized by a variety of techniques including X-ray diffraction (XRD), solid state 13C and 29Si NMR spectroscopy, thermogravimetric analysis (TGA) and nitrogen sorption measurements. Direct NMR evidence for the amine functional groups in close proximity to the Q3 SiOH species in amino-functionalized mesoporous silica SBA-1 is provided by two-dimensional 29Si{1H} HETCOR-based NMR.
In the third part, highly ordered SBA-15 mesoporous silica contains phosphonic acid groups are synthesized via co-condensation of tetraethylorthosilicate (TEOS) and diethylphosphatoethyltriethoxysilane (PETES) using Pluronic 123 (P123) as a structure-directing agent under acidic conditions. The presence of functional group in th resultant material are confirmed by 29Si{31P} REDOR NMR study.
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