Structural, dielectric and optical characterization of PPy-doped PVDF-PVP composite films with a machine learning approach

In the present study, the conducting polymer polypyrrole (PPy) was grown into the matrix of polyvinylidene fluoride (PVDF)-polyvinylpyrrolidone (PVP) using an in-situ polymerization technique. The influence of conducting polymer on the structural, dielectric, and optical characteristics of the PVDF-PVP base matrix was studied. The structural modification due to the conducting polymer in the base matrix was investigated using XRD. The growth of PPy into the matrix of PVDF-PVP was also seen in SEM micrographs. Dielectric properties were measured in the low-frequency range (1 kHz to 2 MHz) and microwave frequency range (200 MHz to 20 GHz). Enhancements in dielectric constant, dielectric loss, and AC conductivity values were observed after incorporating PPy, which were seen to be dependent on the weight percent (wt.%) concentration of PPy in the polymer composite film. The optical properties of these polymer composite films of PVDF-PVP-PPy indicated a reduced band gap after integration of PPy, which reflects the structural changes occurring due to the presence of PPy in the PVDF-PVP matrix. Furthermore, machine learning (ML) models were employed on experimental data to predict the dielectric parameter. The XGBoost model demonstrated the most efficient method among the tested models.