Preparation and characterization of PbO/carboxymethyl cellulose/polyvinylpyrrolidone nanocomposite films

Lead oxide nanoparticles (PbO NPs) and carboxymethyl cellulose (CMC)/polyvinylpyrrolidone (PVP) nanocomposite films were prepared by sol-gel and solution casting methods respectively. The structural properties of the samples were investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM) and Fourier transformation infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) revealed the good dispersion of PbO NPs on the surface of the blend films. CMC film exhibits a transmittance (T) of 72%, increased after mixing with PVP and then decreased to <38% after adding 4.0 wt% PbO NPs. Both the direct and indirect optical band gaps (E-g) of CMC equal to 3.97 and 3.7 eV, respectively. These values were increased after PVP addition and then decreased after loading PbO NPs. The conduction mechanism in CMC/PVP blend has changed from Schottky emission to Poole-Frenkel due to the effects of temperature and PbO NPs content. The effect of adding PVP & PbO NPs on the DC conductivity and the activation energy E-a values of the CMC are discussed. The dielectric constant (epsilon) was investigated in the frequency and temperature ranges of 1 kHz-1.0 MHz and 293-393 K respectively. Its values depend on both the PbO content and temperature. The AC conductivity sigma(ac) was increased with increasing PbO content. The correlated barrier hopping (CBH) was found to be the most appropriate mechanism for explaining the AC conduction behavior. POLYM. COMPOS., 39:3712-3725, 2018. (c) 2017 Society of Plastics Engineers