Abstract

Radial zinc oxide (ZnO) was prepared using a new user-friendly chemical process, and the surface was modified by adsorbing polyaniline (PANI) as a charge carrier. The modified ZnO (PZnO) was used to prepare poly(vinylidene fluoride) (PVDF) PZnO nanocomposites with improved dielectric properties. The structural morphology of the fillers was examined using powder X-ray diffraction and then correlated with observations from high-resolution transmission electron microscopy. A new characterization technique was used to study the maximum adsorption limit by performing solvent relaxation nuclear magnetic resonance experiments, and the results suggested that a maximum of 10% PANT is adsorbed onto the ZnO. The adsorbed PANI acted as an interface and stabilized the ZnO in PVDF solution due to strong interactions between the matrix and fillers. An electron spin resonance (ESR) study was carried out to characterize the spin resonance of ZnO and PZnO. The adsorption of PANI onto ZnO generated charge carriers, and hence, under the influence of a magnetic field, the samples exhibited dissimilar resonance behavior. Dielectric studies of the PVDF PZnO composites were performed, and the PVDF ZnO composites and pure PVDF were compared over a wide range of frequencies (0.01 Hz-1 MHz) and temperatures (25-90 degrees C). The results suggest that the PVDF-7.5PZnO composite showed a significantly improved dielectric constant with a decrease in dielectric loss (0.2), most likely because the adsorption of PANI onto ZnO led to strong interactions between the matrix and fillers and enhanced the interfacial polarization in PVDF.