College of Resources and Environment, Shaanxi University of Science & Technology, Xi'an 710021, China.
J Colloid Interface Sci. 2013 Oct 1;407:155-63. doi: 10.1016/j.jcis.2013.06.045. Epub 2013 Jun 27.
Polystyrene/silica core-shell spheres were fabricated using polystyrene as templates by hydrolysis and condensation of tetraethyl orthosilicate through a sol-gel process, in which polystyrene was synthesized by emulsion polymerization. Then, hollow silica spheres were obtained after selective removal of the organic polystyrene core from the polystyrene/silica core-shell spheres by tetrahydrofuran etching. The effect of hollow silica spheres on water vapor permeability, mechanical property, and water uptake of polyacrylate membrane were investigated. The microstructure analysis shows that the mean size and wall thickness of hollow silica spheres are 170 nm and 20 nm, respectively. The silica shells consist of amorphous silica seed assembly with a broad size distribution, which roughen the surfaces of hollow silica spheres greatly. The specific surface area of hollow silica spheres is bigger than that of polystyrene/silica core-shell spheres. Hollow silica spheres can significantly improve water vapor permeability of polyacrylate membrane, but lead to the reduction in mechanical property.
聚苯乙烯/二氧化硅核壳球通过溶胶-凝胶法，以聚苯乙烯为模板，四乙氧基硅烷水解缩合制得，其中聚苯乙烯通过乳液聚合合成。然后，通过四氢呋喃刻蚀选择性地从聚苯乙烯/二氧化硅核壳球中除去有机聚苯乙烯核，得到空心二氧化硅球。考察了空心二氧化硅球对聚丙烯酸酯膜水蒸气透过性、力学性能和吸水率的影响。微观结构分析表明，空心二氧化硅球的平均粒径和壁厚分别为 170nm 和 20nm。二氧化硅壳由具有较宽分布的无定形二氧化硅种子组装而成，这使得空心二氧化硅球的表面非常粗糙。空心二氧化硅球的比表面积大于聚苯乙烯/二氧化硅核壳球。空心二氧化硅球可以显著提高聚丙烯酸酯膜的水蒸气透过率，但会降低力学性能。
