Impact of hot rolling on the structure and electrical properties of solution cast PVDF films and its optimization in sensors

Polyvinylidene fluoride (PVDF) has attracted significant attention for its unique piezoelectric and ferroelectric properties. However, traditional processing primarily results in the non-polar α phase, limiting its applications. This study prepared PVDF films via solution casting followed by rolling at various temperatures to promote the transition to the β phase. High-temperature rolling significantly enhanced the β phase content, improved the microstructure and orientation of the films, and markedly enhanced the piezoelectric and ferroelectric properties. Particularly, the films rolled at 90 °C exhibited a higher relative content of the β phase, showing exceptional piezoelectric performance with a d 33 value of 26 pC/N and ferroelectric properties with a remanent polarization (P r ) of 13.69 μC/cm 2 . Additionally, hot rolling at higher temperatures notably improved the mechanical properties, enhancing both tensile strength and elongation at break. The optimized PVDF films present broad application prospects in areas such as sensors. This study provides a method and theoretical guidance for the preparation of high-performance PVDF-based functional materials.