无皂乳液聚合法制备聚甲基丙烯酸甲酯包覆厚度可控的纳米核-壳二氧化硅微球

用改进的Stöber法和无皂乳液聚合法制备窄分布的二氧化硅/PMMA核-壳纳米微球. 用改进的Stöber法将3-乙氧基甲基丙烯酸丙基硅烷(MPS)修饰在纳米的二氧化硅表面后, 用无皂乳液聚合法制备核-壳纳米微球. 该法简单有效且得到厚度均匀的聚合物包覆层. 随着单体MMA用量的增加, 用动态光散射法测量, PMMA壳层的厚度从6.4 nm增加到96.3 nm. 热重分析表明, PMMA的含量从22.25%增加到93.41%. 扫描电子显微镜和透射电子显微镜结果表明, 得到的是包覆良好、表面光滑的核-壳无机/聚合物纳米微球.

Preparation of Monodisperse Silica/PMMA Core/Shell Nanoparticles with Controllable Shell Thickness by Soap-free Emulsion Polymerization

Monodisperse silica/PMMA core-shell nanoparticles were prepared by soap-free emulsion polymerization and the modified Stöber process. 3-Methacryloxy-propyltriethysilane(MPS) tailored surfaces of silica can be obtained from sol-gel preparation with Stöber process. The core-shell nanoparticles prepared from the soap-free emulsion polymerization were efficiently created with a uniform polymer shell. The shell thickness of PMMA was increased from 6.4 nm to 96.3 nm as judged by dynamic light scattering with increasing the amount of the MMA monomer. Thermogravimetric analysis result indicates the mean PMMA contents of 22.25%—93.41%. The results of SEM and TEM show a well-defined core-shell morphology for the inorganic/PMMA nanoparticles.