Spectroscopic insights into the optical, impedance, and dielectric behaviour of PVA-glutaraldehyde-carbon composites

The poly vinyl alcohol doped with Glutaraldehyde and Carbon (PVA-GL-C) films were prepared by solution casting method. The distribution of Carbon with crystalline characteristics, the surface morphology studies, and the crosslinking process of glutaraldehyde were investigated using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and Attenuated Total Reflection-Fourier Transform Infrared Radiation (ATR-FTIR) respectively. Ultraviolet-visible (UV-Vis) spectroscopic analyses study the group configurations and changes in the direct, indirect, and forbidden band gaps. The least direct, indirect, and forbidden bandgap of 1.63, 1.26 and 1.57 respectively were found for PVA film with 0.4 % of carbon. The dielectric, electric modulus, and impedance properties are investigated using an Impedance analyser. The carbon-doped PVA-GL-C composite films show an increase in impedance with the presence of glutaraldehyde and changes in alternating current conductivity. The PVA film exhibited 0.7MS2, whereas PVA+ 0.1 %C+ 10 %GL film showed 2.65MS2 of impedance and decreased tangent loss by 61.85 % +/- 2. 2.16MS2 and 3.63MS2 of grain resistance were observed for PVA+ 0.1 %C+ 10 %GL and PVA+ 0.4 %C, respectively. The films exhibited lossless behaviour at higher frequencies and variance in dielectric quantities that are suitable for microwave electronic applications.