【摘要】 采用溶胶 -凝胶法 ,以正硅酸乙酯 (TEOS)为前驱体 ,以不同分子量的聚乙二醇 (PEG)为改性剂 ,制备结构可控的多孔 Si O2 干凝胶 .结果表明 :PEG限制了 TEOS的水解反应 ,进而对溶胶粒子的表面进行修饰 ,形成“粒子团 -PEG”聚集体及短程有序的环状网络结构 ,由此对 Si O2 干凝胶的结构性质进行调控 .经真空热处理后 ,PEG等有机残留物被脱除的同时 ,Si O2 -PEG干凝胶柔性骨架得到加强 ,孔分布更趋集中 ,干凝胶结构的热稳定性得到进一步提高 .更多还原

【Abstract】 The porous SiO₂ xerogels with controlled structure were obtained from TEOS in the presence of PEG by sol-gel method. The results showed that PEG restrained the hydrolysis reaction of TEOS, and then modified the surface of sol particle to form the PEG-clusters （i.e. the ring-like networks in short order）. As a result, the addition of PEG could adjust the texture properties of SiO₂ xerogels. It has been found that the SiO₂ xerogel has a stronger flexible skeleton, narrower pore distribution, and higher thermal stability with the removal of the residue organic（such as PEG and so on） by vacuum heat-treatment.更多还原