通过RAFT聚合制备SiO2/接枝共聚物纳米杂化粒子

以二氧化硅(SiO2)纳米粒子表面键接的二硫代苯甲酸酯作为可逆加成-断裂-链转移(RAFT)聚合反应的链转移剂, 在室温下引发苯乙烯和马来酸酐进行表面RAFT交替共聚反应, 制得了SiO2/苯乙烯-alt-马来酸酐杂化材料. 通过聚氧化乙烯(PEO)的羟基与马来酸酐的酯化反应, 将PEO接枝到SiO2纳米粒子的表面, 增加了硅粒子的生物相容性. 用FTIR, TGA和TEM对杂化材料的结构、组成和形貌进行了表征.

Preparation of SiO2/Graft Copolymer Hybrid Nanopartciles by RAFT Copolymerization

By condensation reaction of the hydroxyl groups on the silica nanoparticle surface with coupling agent KH-560,epoxy groups were covalently attached to silica nanoparticles.The reversible addition-fragmentation chain transfer(RAFT)agent,dithiobenzoate,was anchored on the surface of the silica nanoparticles by the reaction of carboxylic acid in the RAFT agent,carboxypropyl dithiobenzoate with the epoxy group.The resultant RAFT agent was used in the surface RAFT copolymerization of styrene(St)and maleic anhydride(MAh)at room temperature,and SiO_2/poly(St-alt-MAh)hybrid materials were obtained.Since MAh is highly reactive,poly(ethylene oxide)methyl ether(MPEO)was grafted onto the copolymers on the surface of particles via reaction of hydroxyl group in MPEO with MAh,forming SiO_2/PSt-alt-(MAh-g-PEO)] composite particles.The composition,structure and morphology of the composite particles were confirmed via FTIR,TGA and TEM.This provides a new approach to graft biocompatible and hydrophilic PEO onto silica particles.