Enhanced quality factor of polyvinyl formal (PVF) based nanocomposites filled with zinc oxide and carbon black nanoparticles for wireless sensing applications

Abstract

The present article deals with the preparation of polyvinyl formal based nanocomposites filled with zinc oxide (ZnO) and carbon black nanoparticles using colloidal blending technique. To explore the electrical and structural properties, PVF/ZnO/CBNP nanocomposite films were characterized using Fourier transform infrared (FTIR) spectroscopy, X- Ray diffraction (XRD) and Scanning electron microscopy (SEM). The surface morphology of these nanocomposite films was evaluated using polarized optical microscopy (POM). The structural change in PVF nanocomposite was achieved by incorporating ZnO and CBNP, by homogeneous distribution in polymer nanocomposite. The electrical properties such as impedance and quality factor (Q – factor) of PVF/ZnO/CBNP composite films were elucidated using impedance analyzer in the wide range of frequency from 50 Hz – 20 MHz and temperature in the range 50°C – 150°C. Quality factor was measured as a function of temperature (50 – 150°C) and wide range of frequency from 50 Hz - 20 MHz. The PVF/ZnO/CBNP nanocomposite exhibits high Q-factor (439) for neat PVF films. The incorporation of ZnO at 10% decreases Q-factor to 36.1. Incorporation of CBNP at 5% and ZnO at 5% further reduces the Q-factor to 13.7. With further increase in CBNP content, the Q – factor was found to decrease7.38. Impedance values of PVA/ZnO/CBNP nanocomposites varied at different filler loading in PVF at 3% of CBNP (3.54 X 107Ω) to 10% of CB (1.48 X 107Ω). Increase in the CBNP wt% in PVF shows enhanced conductivity. Thus, based on the above results the PVF/ZnO/CBNP nanocomposites can be used for high – k capacitor applications and also for wireless sensing applications.