A novel method for surface modification of nanoparticles based on control of charge environment

Abstract

A novel procedure for surface modification of SiO2 nanoparticles is described. Tetraoctylammonium bromide was introduced to modification system for the purpose of controlling the surface charge environment of SiO2 nanoparticles. Then, the SiO2 nanoparticles were treated with the coupling agents firstly, followed by radical grafting polymerization in non-aqueous system to graft Poly (methyl methacrylate) chains onto the surface of modified SiO2 nanoparticles. Fourier transform infrared spectroscopy, thermogravimetric analysis, high-resolution X-ray photoelectron spectra, and 13C nuclear magnetic resonance were used to characterize the modification effect of SiO2 nanoparticles. The results indicated that the method we described is an effective way to modify the surface of nanoparticles. And the morphology and characteristic of SiO2 nanoparticles were characterized by transmission electron microscopy (TEM), quasielastic laser light scattering (QELS), dynamic contact angle. The results of TEM and QELS demonstrated that nanosilica with an average size of 85.8 nm was prepared. The reduction of the contact angle indicated the increase in hydrophobicity of nanosilica. The result of controlling the surface charge environment of SiO2 nanoparticles was characterized by zeta potential. By using this modification method, nanoparticles are of great potential to synthesize versatile organic/inorganic nanocomposite.