Preparation of well-ordered nanoporous materials by using the colloidal array of silica nanopsheres

近年来，我们首次提出了一种液相法制备尺寸均匀的二氧化硅纳米球(SNSS)及其在溶剂挥发过程中的三维有序排列的方法。首先，通过种子再生长的方法成功地实现了球体尺寸在14~550 nm的宽范围内的控制。利用二氧化硅纳米球胶体阵列的受限空间合成方法制备了钽酸钠(NaTaO_3)，NaOH和Ta_2O_5在纳米二氧化硅胶体阵列(SNSS)的孔径为20 nm的三维介孔碳孔中进行水热反应。成功制备了三甲基硅化含钛介孔二氧化硅纳米球(Ti-MSNSS)。三甲基硅基化改善了材料的疏水性，其形貌和钛物种的配位保持不变。由此制备的三甲基硅烷化钛MSNS对各种大体积烯烃的环氧化反应表现出较高的催化性能

A liquid-phase method for preparing uniform-sized silica nanospheres(SNSs) 12 nm in size and their three-dimensionally ordered arrangement upon solvent evaporation have recently been pioneered by us. Firts, the successful control of the sphere sizes in the wide range from 14 to 550 nm has been achieved by the seed regrowth method. The confined space synthesis method using the colloidar array of silica nanospheres has been applied to the preparation of sodium tantalate(NaTaO_3); hydrothermal reaction of NaOH and Ta_2O_5 was carried out in the pores of three-dimensional mesoporous carbon, which was replicated by the colloidal array of silica nanospheres(SNSs) 20 nm in size. Trimethylsilylated Ti-containing mesoporous silica nanospheres(Ti-MSNSs) have been successfully prepared. The trimethylsilylation improved a hydrophobicity of the material with its morphology and the coordination of Ti species intact. Thus prepared trimethylsilylated Ti-MSNSs exhibited a higher catalytic performance in the epoxidations of various bulky olefins