Achieving β-edge-on alignment in nanocomposite fibres by synergistic interaction of PVDF dipoles and hydroxylated BaTiO₃ nanoparticles

This study investigates the influence of various hydroxylated BaTiO₃ nanoparticles and spin velocities on the β-chain degree of alignment in PVDF nanocomposite fibres. A homemade electro-centrifugal spinning system was used to produce the PVDF nanocomposite fibres. Pure BaTiO₃ nanoparticles (C-BTO) were synthesized via the sol-gel method, yielding an average particle size of 18 nm. The hydrogenated BaTiO₃ nanoparticles (H-BTO) were primarily responsible for inducing a high degree of beta-edge orientation, a phenomenon underexplored in previous PVDF/BaTiO₃ systems. Compared to unmodified C-BTO, H-BTO significantly increased the β-chain degree of alignment in the resulting nanocomposite fibres by 58%. Increasing the H-BTO concentration further enhanced β-chain alignment, reaching optimal performance at 50 wt.% loading. At this concentration, the β-fraction and alignment degree reached 96% and 0.95, respectively. The optimum piezoelectric nanogenerator (PENG) exhibited maximum output values: an open-circuit voltage (VOC) of 51 V, a short-circuit current (ISC) of 5.1 μA, and a power density of 27 μW·cm⁻². As a practical demonstration of its efficiency, six red LEDs were directly illuminated by the optimum PENG.