钛酸四丁酯水解制备聚苯乙烯/二氧化钛核壳粒子及空心二氧化钛微球

通过无皂乳液聚合方法制备了阳离子型及阴离子型聚苯乙烯(PSt)乳胶粒,并对后者用γ-氨丙基三乙氧基硅烷(KH550)进行了表面改性制得了乳胶粒表面载正电荷的乳液.在乙醇与水的混合溶剂中,分别使用以上3种PSt乳胶粒为核加入钛酸四丁酯制备了核壳型PSt/TiO2复合粒子.结果显示,仅在使用经KH550改性的阴离子PSt乳...

PREPARATIONS OF PSt/TiO2 CORE-SHELL COMPOSITES AND HOLLOW TiO2 PARTICLES BY HYDROLYSIS OF TETRABUTYL TITANATE IN PRESENCE OF PSt LATEX PARTICLES

Cationic and anionic PSt(polystyrene) latexes were synthesized using emulsion polymerization.The anionic PSt particles were treated using γ-aminopropyl triethoxysilane(KH550) and the surface of the particles in this anionic latex was thus changed from negatively to positively charged.PSt/TiO2 composite particles were then prepared through hydrolysis of TBT(tetrabutyl titanate) in a mixture of ethanol and water,in the presence of the above 3 types of PSt latex particles,respectively,i.e.anionic PSt,cationic PSt and the anionic PSt particles treated using KH550.Results showed that a clear PSt/TiO2 core-shell structure was obtained only by using the KH550 treated anionic PSt particles.When these core-shell composite particles were dispersed into tetrahydrofuran to dissolve PSt core,TiO2 hollow particles were clearly observed under TEM.The study on the influence of KH550 amount on PSt/TiO2 core-shell formation revealed that 0.1 g of KH550 was enough to change the anionic PSt particles from negatively to positively charged,more KH550 did not contribute to the formation of PSt/TiO2 core-shell particles.Using 5 mL of the KH550 treated PSt latex of 9.4% solids,appropriate amount of TBT should be controlled between 1 g to 2 g in order to get well formed TiO2 hollow particles.The mechanisms of the PSt/TiO2 core-shell formation and of TiO2 hollow particles were discussed.