Improved tensile strength and ferroelectric phase content of self-assembled polyvinylidene fluoride fiber yarns

An electrospinning method to obtain well-aligned self-assembled PVDF fibers in the form of yarn structures is presented. Post-treatments such as stretching at 100 °C and annealing improve the tensile modulus and strength of the fibers by 17 and 41%, respectively. The results reveal that post-treatment on fiber yarns induce crystallinity and β-crystalline phase formation, which in turn impart a noticeable effect on the strength and stiffness of the fibers. An ≈10% improvement in the ferroelectric β-crystalline phase fraction is estimated for the post-treated yarns. Such yarn structures with improved strength and ferroelectric β-phase content can be useful for nanoscale and microscale electronic devices. A method to improve the ferroelectric phase content and tensile strength of PVDF fibers is presented. Well-aligned PVDF fibers collected as yarn structures are hot-stretched at 100°C and subsequently annealed to induce crystallinity and formation of the β-crystalline phase. It is estimated from XRD peaks and FTIR spectra that the β-phase content increases by 10% for the post-treated yarns.