This work investigates fabrication of aerogel foams from syndiotactic polystyrene (sPS) using silica-based Pickering emulsion method. A large fraction of micrometer size voids (macrovoids) is created inside porous thermo-reversible sPS gels by dispersing water droplets without the use of surfactants before gelation of sPS solution. The method used in this work alleviates two critical concerns of surfactant-stabilized emulsion templating method, namely the sensitivity of emulsion stability to temperature and the difficulty of removing the surfactants from aerogel foams. Hydrophobic silica particles of diameter 50-70 nm are used to stabilize Pickering emulsion of micrometer size water droplets in sPS solution in toluene emulsions at 110 °C. Emulsion stability shows weak dependence on temperature and on water volume fraction. The sPS chains form thermo-reversible gels when cooled to room temperature and lock the water droplets inside the gel. The aerogel foams, recovered via supercritical drying, show high porosity and coexisting macrovoids and macropores. The most probable macrovoid size varies in the range of 50-600 μm and is strongly dependent on water volume fraction. The silica particles are found localized on macrovoid surfaces.

这项工作研究了间规聚苯乙烯（sPS）使用基于二氧化硅的Pickering乳液法制备气凝胶泡沫的方法。在sPS溶液胶凝之前，无需使用表面活性剂即可分散水滴，从而在多孔的热可逆sPS凝胶内形成了很大一部分的微米级空隙（宏观空隙）。这项工作中使用的方法减轻了表面活性剂稳定的乳液模板方法的两个关键问题，即乳液稳定性对温度的敏感性和从气凝胶泡沫中去除表面活性剂的难度。直径为50-70 nm的疏水性二氧化硅颗粒用于在110°C下将微米级水滴的Pickering乳液稳定在sPS溶液中的甲苯乳液中。乳液稳定性显示出对温度和水体积分数的弱依赖性。sPS链在冷却至室温时会形成热可逆凝胶，并将水滴锁定在凝胶内。通过超临界干燥回收的气凝胶泡沫显示出高孔隙率，并同时存在大孔和大孔。最可能的大孔隙尺寸在50-600μm的范围内变化，并且很大程度上取决于水的体积分数。发现二氧化硅颗粒位于大孔隙表面上。