Tailoring Morphology for Enhanced Piezoelectricity in PVDF-Rich Ternary Blends: The Role of Hot Pressing and composition for Flexible Energy Harvesters

• A novel ternary polymer blend (PVDF/PAN/PEO) is designed for solid state electrolyte membranes. • Hot-Pressing significantly enhances crystallinity and mechanical strength but reduces ionic mobility. • Electrical modulus analysis reveals suppressed electrode polarization and slower ion relaxation after processing. • XRD/DSC analysis quantifies crystallinity and distinguishes long-range order from thermal enthalpy. The development of Polymer-based material with enhanced thermal, mechanical, and dielectric characteristics is essential for flexible electronics and energy harvesting. In this study, PVDF-rich ternary blends of polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), and polyethylene oxide (PEO) were fabricated via solution casting with varying PAN and PEO concentrations, followed by hot pressing. Detailed characterization using XRD, DSC, SEM, tensile testing, and dielectric spectroscopy was carried out. Hot pressing improved crystallinity and β-phase content, leading to enhanced dielectric and piezoelectric performance. Among the compositions, the PVDF/PAN/PEO (60/25/15) blend exhibited superior multifunctionality, with 86% crystallinity, 72% β-phase content, a dielectric constant of 17.8, and 22% elongation. SEM revealed improved morphology and interfacial compatibility in PVDF-rich films. Oscilloscope measurements confirmed a significantly higher piezoelectric output (7.5 V). These results demonstrate the importance of PVDF-rich composition and thermal processing in optimizing multifunctional properties for wearable sensors, flexible electronics, and next-generation piezoelectric devices.