Optical properties and broadband radio frequencies dielectric performance of solution cast-hot pressed PVDF/PMMA/BaTiO₃ nanocomposite films

The solution cast (SC) prepared polymer nanocomposite (PNC) films, based on poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA) blend host matrix with varying amounts of barium titanate (BaTiO₃) as nanofiller, were thermally treated through standardized hot pressed (HP) procedure at 160 °C under the pressure of 2 tons. The optical characterization including absorbance, reflectance, and percentage transmittance for UV–vis radiations of 200–800 nm, direct and indirect energy band gaps, Urbach energy, refractive index, extinction coefficient, optical range dielectric permittivity and optical conductivity as well as non-linear optical parameters of these solution cast-hot pressed (SC-HP) PNC films are performed and confirmed their dependency on the nanofiller concentrations. These SC-HP processed PNC films showed reduced UV–vis absorbance, direct energy band gap, and the degree of crystallinity of the PVDF crystalline phase whereas the crystallite melting temperature significantly enhanced in comparison to the same composition SC prepared PNC films. The dielectric permittivity and electrical conductivity values, at 27 °C, for these thermally treated PNC films are improved appreciably over the broadband radio frequency range of 1 MHz to 1 GHz. The technologically favoured changes in various optical and dielectric parameters establish the appropriateness of the thermal treatment process for envisaging applications of these PNCs in advances of high-performance flexible-type optoelectronic and radio electronic devices.