Effect of Bismuth Ferrite Nanoparticles on Physicochemical Properties of Polyvinylidene Fluoride-Based Nanocomposites

Bismuth ferrite (BiFeO3, BFO) is one of the few single-phase crystalline compounds exhibiting strong multiferroic properties at room temperature, which makes it promising for use in various fields of science and technology. The remarkable characteristics of BFO at the nanoscale position it as a compelling candidate for enhancing the functionalities of polymeric nanocomposite materials. In this study, we explore the fabrication of polyvinylidene fluoride (PVDF) nanocomposites with a variable content of BFO nanopowders (0, 5, 10, 15, 20, and 25 wt%) by solution casting in the form of thin films with the thickness of ~60 µm. Our findings reveal that the presence of BFO nanoparticles slightly facilitates the formation of β- and γ-phases of PVDF, known for their enhanced piezoelectric properties, thereby potentially expanding the utility of PVDF-based materials in sensors, actuators, and energy harvesting devices. On the other hand, the increase in filler concentration leads to enlarged spherulite diameter and porosity of PVDF, as well as an increase in filler content above 20 wt% resulting in a decrease in the degree of crystallinity. The structural changes in the surface were found to increase the hydrophobicity of the nanocomposite surface. Magnetometry indicates that the magnetic properties of nanocomposite are influenced by the BFO nanoparticle content with the saturation magnetization at ~295 K ranging from ~0.08 emu/g to ~0.8 emu/g for samples with the lowest and higher BFO content, respectively.