Synthesis and characterization of (hydroxypropyl)cellulose/TiO2 nanocomposite films

A new method of synthesis of TiO2 nanoparticles as well as preparation of the organic-inorganic hybrid nanocomposite films of (hydroxypropyl) cellulose (HPC)/TiO2 is presented. At the first stage, the oxotitanium hydrogel phase was obtained by the mineralization of (tetra-isopropyl)orthotitanate (TIPT) modified by the methacrylic acid (MAA) in 15 wt% solution of H2O2 at room temperature and subsequent annealing at the temperature of 85 degrees C. The crystallization of the nanoparticles of TiO2 was conducted at the oxotitanium hydrogel phase at temperatures around 120 degrees C in the closed vessel. Nanocomposite hybrid films were prepared by the casting method from a solution of HPC and TiO2 nanoparticles in the water. The films of nanocomposite with 10 mu m thickness are transparent to visible light and have a lower glass transition temperature compared with HPC in the bulk. This shift of the glass transition is interpreted in terms of packing density of HPC in the interface of HPC nanocomposite with TiO2. The X-ray diffraction pattern of the nanocomposite film suggests a lower amount of mesomorphic phase of HPC in the composite compared with HPC in the bulk. Copyright (C) 2007 John Wiley & Sons, Ltd.