三嵌段共聚物合成 SiO2中孔材料的制备化学

采用溶胶一凝胶法，以正硅酸乙酯（ＴＥＯＳ）为前驱体，添加聚氧乙烯醚（ＰＥＯ）一聚氧丙烯醚（ＰＰＯ）一聚氧乙烯醚（ＰＥＯ）共聚物为模板剂制备结构可控的ＳｉＯ２中孔材料，通过ＢＥＴ、ＴＧ／ＤＴＡ、ＦＴ－ＩＲ、２９ＳｉＮＭＲ等分析手段，考察了不同条件下溶胶一凝胶制备化学及其热处理对ＳｉＯ２中孔材料结构性质的影响规律和内在本质．结果表明：通过调节聚合度和添加量以及溶胶老化时间，可以对ＳｉＯ２中孔材料织构性质进行有效的调控;同时由于该共聚物在不同气氛温度下的脱除机理不同，从而对材料的结构性质影响也有所不同;经真空热处理后，ＳｉＯ２中孔材料柔性骨架得到加强，孔分布更趋集中．

Preparation of Mesoporous SiO2 via of Triblock Copolymer

The mesoporous SiO_2 xerogels with controlled texture were obtained using TEOS asprecursor in the presence of Polyethylene Oxide (PEO)-Polypropylene Oxide (PPO)-PolyethyleneOxide (PEO) by sol-gel method. By means of BET, TG/DTA, FT-IR and 29Si NMR analysis,the sol-gel chemistry was investigated and the effects of heat treatment in different conditions werealso discussed. The results show that the triblock copolymer molecular chain, additive amountand ageing time of SiO2 sol can adjust available the texture properties of mesoporous SiO2, and indifferent atmospheres, the removed mechanism of such copolymer is different, which results in thedifferent effects on the mesoporous SiO2. As a result, the mesoporous SiO2 has stronger flexibleskeleton, narrower pore distibution, and higher thermal stability by vacuum heat-treatment.