Enhanced electroactive β-phase formation in electrospun poly (vinylidene fluoride-co-hexafluoropropylene) nanowires with gold nanoparticles

As a representative piezoelectric polymer, poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) has been widely used in sensors transducers and actuators. In this paper, gold nanoparticles (AuNPs) are prepared and doped into the PVDF-HFP solution to enhance the piezoelectric property of electrospun PVDF-HFP nanowires. The results indicate that proper amounts of AuNPs within the nanowires can improve the piezoelectric phase in PVDF-HFP. Then, a nanogenerator was prepared using the PVDF-HFP/Au nanowires to verify the increase in piezoelectric performance. Experimental results show that compared with PVDF-HFP nanogenerator without AuNPs doping, the output voltage is increased by about two times, while the output current is doubled for the PVDF-HFP/Au nanogenerator. Furthermore, systematic molecular dynamics (MD) simulations are conducted to elucidate the physical mechanism of AuNPs enhanced β-phase formation in PVDF-HFP. Our results show that the adsorption and electrostatic interaction between the AuNPs and the PVDF chains promote the electroactive β-phase formation, and also significantly increase the tension and poling effect during electrospinning process, which is the origin of the enhanced electroactive phase formation in electrospun PVDF-HFP nanowires.