Abstract
We report facile syntheses of amino-functionalized large-pore mesoporous silica materials by co-condensation, using the carboxylate -terminated triblock Pluronic copolymers as structural directing agents and pre-hydrolyzed silica source of TEOS. The carboxylate end-groups were found to facilitate the hydrolysis and condensation of silica precursors and overcome the problem of the disturbed kinetics by the presence of the amino-functional silanes. The usage of the carboxylate -terminated triblock copolymers was also found to accelerate the formation of three-dimensional ordered structures of copolymer/silica hybrids in solution and enhance the degree of silica condensation of the materials. By using the carboxylate -terminated triblock copolymers, we have successfully prepared the amino-functionalized mesoporous SBA-15, KIT-5 and SBA-16 silica materials. Their elemental and structural characterizations by powder X-ray diffraction, nitrogen physisorption analysis, thermal analysis, solid-state nuclear magnetic resonance spectroscopy and electron microscopies have been performed. We also applied the amino-functionalized KIT-5 silicas to prepare the supported gold nanoparticles. The images of transmission electron microscopy revealed that the gold nanoparticles were uniform in size and were well dispersed in KIT-5 silicas. The distribution of gold nanoparticles reflected the distribution of the amino functional groups in the host KIT-5 silica materials.