Functionalized Si3N4 nanoparticles modified with hydrophobic polymer chains by surface-initiated atom transfer radical polymerization (ATRP)

Abstract

In order to improve the dispersibility of nanoparticles in polymer matrix, a feasible processing way for grafting high density hydrophobic polymer on the surface of silicon nitride (Si3N4) nanoparticles was carried out by an atom transfer radical polymerization (ATRP) method. The ATRP initiators were first immobilized on the surface of Si3N4 nanoparticles by using 3-aminopropyltriethoxysilane coupling agent and 2-bromoisobutyryl bromide, and then the polymerization of methyl methacrylate was initiated and propagated on the surface of Si3N4 nanoparticles by ATRP reaction. The chemical groups, size, morphology, grafting content, and colloidal thermal stability of PMMA–Si3N4 particles were studied by Fourier transform infrared (FTIR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). Results indicate that the grafting of polymer on the surface of Si3N4 nanoparticles is successful and the grafting content of PMMA reaches 60.4%. Moreover, the grafted polymer chains have changed the surface properties of Si3N4 nanoparticles and enhanced their dispersibility in organic media.