Influence of nanostructured TiO2 additives on some physical characteristics of carboxymethyl cellulose (CMC)

Abstract

TiO2 nanoparticles, successfully prepared by sol-gel method, were added with different contents to CMC solution to obtain CMC/TiO2 nanocomposite. The structure and particle size of the TiO2 nanoparticles, embedded in the CMC matrix, were identified by X-ray diffraction (XRD), and transmission electron microscopy (TEM) techniques, with particle size in the range of 20–40 nm. The additives have a significant effect on the particle size distribution and physical properties of CMC/TiO2. The optical and electrical properties of CMC/TiO2 were characterized by means of UV–VIS spectroscopy and electrical methods, respectively. The electrical activation energy ΔE for DC conduction decreases with increasing in TiO2 ratio. The ac conductivity depends on the temperature and frequency according to SPH model for CMC polymer and CBH model for CMC/TiO2 nanocomposites. The dielectric constant ɛ1 and dielectric loss ɛ2 for all samples increase with increasing temperature and decrease with increasing the frequency. The optical band gap transforms from indirect in case of CMC polymer into direct band gap in case of CMC/TiO2 nanocomposites. Moreover, the optical band gap was investigated under different doses of gamma irradiation. The band gap is slightly increased by increasing the doses of gamma irradiation.