Tuning the structural, optical, electrical, and dielectric properties of PVA/PVP/CMC ternary polymer blend using ZnO nanoparticles for nanodielectric and optoelectronic devices

Abstract

Nanocomposite films made of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and carboxymethylcellulose (CMC) and filled with different concentrations of zinc oxide nanoparticles (ZnO NPs) were created using the solution casting technique. Investigation and discussion were conducted about the effect of ZnO NPs on the pure PVA/PVP/CMC mixture's structural, optical, and electrical features. According to transmission electron microscopy (TEM) and X-ray diffraction (XRD) examinations, the size of the ZnO NPs produced is between 6 and 17 nm and has a hexagonal phase. The X-ray studies of the filled films revealed that the crystallinity of the ZnO NPs has grown at the expense of the PVA/PVP/CMC matrix. According to Fourier Transform Infrared (FTIR) analysis, the main vibrational peaks of PVA, PVP, CMC, and Zn–O varied after filling randomly. For the pure blend, the UV/Vis-NIR transmittance spectra displayed a large absorption peak at 210 nm that could be attributed to the π→π* transitions. After filling, the prepared composites showed a significant decrease in the average transmittance percentage and the appearance of a new small peak at 370 nm that related to the absorption of ZnO NPs. The optical energy gap (Eg), calculated using the indirect and direct allowed transition, was discovered to be reduced as the ZnO NPs content increased. At room temperature, the samples' dielectric characteristics, impedance, and AC conductivity were investigated over a wide frequency range (10−1 to 107 Hz). When the ZnO NPs content was raised, it was seen that the AC conductivity, dielectric loss, and dielectric constant were enhanced. In order to determine the equivalent electrical circuit for each sample, Z′ and Z″ impedance components were analyzed. Due to these remarkable improvements in electrical and optical properties, these nanocomposite films are a potential competitor for use in optoelectronic devices like sensors.