层间组装SiO2-TiO2粘土材料的制备与表征

以(C2H5O)4Si和Ti(OC4H9)4为硅源和钛源，采用溶胶-凝胶法制备SiO2-TiO2柱化剂，将原土直接加入柱化剂进行柱化反应得到SiO2-TiO2柱撑蒙脱土，对其进行结构和性能表征，考察了柱化剂中Si/Ti比、柱化剂/原土比、柱化反应条件(反应温度和超声处理)及热处理温度对其结构和性能的影响. 结果表明，SiO2-TiO2柱体成功进入蒙脱土层间，在除去未参与柱化反应的柱化剂的条件下，比表面积可达127.2 m2/g，热稳定性提高了70℃，柱化剂中Si含量增加有利于热稳定性的提高，500℃以下焙烧的SiO2-TiO2柱体中Ti以钛氧四面体和八面体形式存在，600℃焙烧可形成锐钛矿晶型.

Preparation and Characterization of Interlayer Assembled SiO2-TiO2 Clay Material

SiO2-TiO2 pillaring agent was synthesized by sol-gel method, and raw clay was added into pillaring agent sol to prepare SiO2-TiO2 pillared montmorillonite. The structural properties of samples were characterized by XRD, N2 adsorption/desorption, TG-DTA and UV-Vis spectrometry techniques. The effects of material ratio and preparation conditions on the structural properties of the final products were investigated. From XRD patterns, the SiO2-TiO2 particles were intercalated into interlayer space of raw clay successfully. When nearly all the SiO2-TiO2 sol not pillared into the clay was removed, the BET speci?c surface area was up to 127.2 m2/g. Thermal stability of the pillared montmorillonite was increased by about 70℃ compared with the raw clay. And the sample with higher content of Si in SiO2-TiO2 particles showed higher thermal stability. Ti was in tetrahedral coordination and octahedral coordination in the pillared montmorillonite calcined below 500℃, and TiO2 was crystallized into anatase at 600℃. Compared with conventional wet method, the new dry method was simpler and more controllable in pillaring reaction process. And the SiO2-TiO2 pillared montmorillonite with regular structure was more easily obtained by the dry method.