Surface Modification of Zinc oxide nanoparticles by Vinyltriethoxy silane (VTES)

Abstract Zinc oxide (ZnO) nanoparticles are hydrophilic in nature and difficult to disperse in polymer matrix due to agglomeration behavior. To disperse the zinc oxide nanoparticles in polymer matrix, it is necessary to modify their surface with hydrophobic groups such as silanes or surfactants. In this article, zinc oxide nanoparticles were modified with various concentration of vinyl triethoxysilane (VTES). To investigate the effect of different concentrations of VTES, on surface modification of zinc oxide nanoparticles, these were characterized using physical characterization techniques such as Fourier-transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), Energy Dispersive X-rays Spectroscopy (EDX), X-ray diffraction (XRD) and contact angle. The results of FTIR, TGA, SEM, EDX and contact angle confirm the surface modification of zinc oxide nanoparticles by VTES. The XRD results show that the crystalline behavior of ZnO nanoparticles was not changed after surface modification by VTES. The crystallite size of surface modified ZnO nanoparticles was calculated using Debye-Scherrer equation and it was found approx 20nm. In FTIR results, some new peaks at 1409, 1014 and 970 cm-1 were observed as compare to unmodified zinc oxide nanoparticles. In contact angle analysis, it was observed that the surface modified zinc oxide nanoparticles have very high contact angle (>150°) in comparison with hydrophilic behavior of unmodified zinc oxide nanoparticles. SEM analysis also showed the improved dispersity of ZnO nanoparticles. Based on characterzation results, it was observed that the 15 wt% VTES concentration is suitable to carry out surface modification of ZnO nanoparticles.