Preparation and characterization of multiresponsive polymer composite microspheres with core-shell structure

摘要

Fe3O4/SiO2/poly (N-isopropylacrylamide-co-N,N-dimethylaminoethyl methacrylate) [P(NIPAM-co-DMA)] multiresponsive composite microspheres with core-shell structure were synthesized by template precipitation polymerization.First,the magnetite nanoparticles were coated with silica and then modified with 3-(trimethoxysilyl)-propyl methacrylate (MPS).Subsequently,the Fe3O4/SiO2 particles grafted with MPS were used to seed the precipitation copolymerization of NIPAM and DMA.The composite microspheres with core-shell structure were superparamagnetic,pH-sensitive,and thermores-ponsive.The swelling ratio (D_(25 °c,PH=3)/D_(50 °C,PH=9))~3 coupling of pH and temperature increased up to 21.2,which was much higher than that without comonomer DMA.