Modification of clay with L-leucine and TiO 2 with silane coupling agent for preparation of poly(vinyl alcohol)/organo-nanoclay/modified TiO 2 nanocomposites film

Abstract

Poly(vinyl alcohol)/organo-nanoclay/modified-TiO 2 nanocomposites films were fabricated by dispersion of modified TiO 2 on the surface of organo-nanoclay in a poly(vinyl alcohol) matrix via an ultrasonic process followed by solution film casting. For this purpose surface-modified TiO 2 nano-particles were added into the poly(vinyl alcohol)/organo- modified Cloisite Na + nanocomposites matrix with 10 wt% organonanoclay. For the improvement of nanoparticles dispersion and increasing possible interactions between nano-particles and polymeric matrix, the surface of the nano-TiO 2 was modified with silane coupling agent (KH550). Also, the negative charge on the silica layer can play an important role in dispersing nanosized TiO 2. Three nanocomposites with different loading of modified-TiO 2 (1, 3 and 6 wt%) were prepared and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission type scanning electron microscope, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis and UV-Vis transmission spectra. In morphological images it was observed that the OMMT was dispersed homogeneously in PVA matrix and modified TiO 2 nanoparticles are regularly dispersed on whole surface of organo-nanoclay layers. TGA results show that thermal stability of poly(vinyl alcohol)/organoclay/modified TiO 2 nanocomposites are enhanced compared with neat PVA. © 2012 Koninklijke Brill NV, Leiden.