摘要
在纳米二氧化硅水分散体系中, 借助于碱性辅助单体1-乙烯基咪唑(1-VID)与未改性纳米二氧化硅表面羟基之间的酸-碱作用, 通过1-VID与甲基丙烯酸甲酯(MMA)的自由基共聚合, 制备了草莓型的SiO2/PMMA复合微球. 整个反应过程中, 纳米二氧化硅无需表面处理, 体系中无需另外加入乳化剂或助乳化剂, 微球表面吸附的纳米二氧化硅对颗粒起稳定作用. 用动态光散射粒度分布仪测得复合微球粒径在120～330 nm之间, 热重分析结果表明, 复合微球中二氧化硅含量介于15%～20%之间. 透射电镜和扫描电镜显示所得复合微球具有草莓型结构, 二氧化硅富集在表面.
Water-borne raspberry-like silica/PMMA nanocomposite particles were prepared via a free radical copolymerization of MMA(methyl methacrylate) with 1-VID(1-vinylimidazole) in the presence of ultrafine aqueous silica sols. The silica needn′t be pretreated or modified and no surfactant was added in this preparation method. The strong acid-base interaction between the surface hydroxyl groups of silica particle with 1-VID was strong enough for promoting the formation of long-stand stable silica/PMMA nanocomposite particles. The average particle sizes of the obtained nanocomposite particles ranged from 120 nm to 350 nm, depending on the precise formulation. Thermogravimetric analysis indicates the silica content in the nanocomposite particles ranged from 15 to 20. TEM and SEM indicate a raspberry-like morphology of the nanocomposite particles.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第7期1352-1355,M008,共5页
Chemical Journal of Chinese Universities
基金
上海市纳米专项(批准号:0352nm039)资助.
关键词
草莓结构
二氧化硅
复合微球
Raspberry-like structure
Silica
Nanocomposite spheres
