Biomimic preparation of highly dispersible silica nanoparticles based polymer nanocomposites

Abstract

Silica nanoparticles (SiO2 NPs) have been widely applied in a number of domains because of their inodorous, non-pollution, optical transparency, chemical inert and good biocompatibility. However, to achieve better performance, surface modification of SiO2 NPs to enhance their dispersibility is generally required. In this paper, a simple, facile and environmental friendly procedure was developed for surface modification of SiO2 NPs with a biocompatible polymer (polyPEGMA) via combination of mussel inspired chemistry and Michael addition reaction for the first time. Firstly, monodisperse SiO2 NPs were prepared by using a slightly modified Stöber process. Secondly, SiO2 NPs were coated with polydopamine (PDA), which was formed through self-polymerization of dopamine in an alkaline aqueous solution. Lastly, the PDA coated SiO2 NPs were facilely conjugated with polyPEGMA, which were synthesized through chain transfer free radical polymerization using cysteamine hydrochloride as chain transfer agent and poly(ethylene glycol) methyl ether methacrylate as the monomer. The successful preparation of these composites was confirmed by a number of characterization techniques including transmission electron microscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis and X-ray photoelectron spectroscopy. This method obviously enhance the dispersion of SiO2 NPs in different organic solvents and aqueous solution. This synthetic method is convenient, effective and environmental friendly, that can be also extended to modify SiO2 NPs with other functional polymers because of the features of mussel inspired chemistry and chain transfer living polymerization.