Dopamine-coated nano-SiO2-modified PVDF piezoelectric composite film

Abstract

This paper presents a solvothermal method to produce polyvinylidene fluoride (PVDF) composite films doped with dopamine-modified nano-silica (dopamine@SiO₂) particles. Combined results of FTIR, SEM and TEM confirm that dopamine is uniformly coated on the surface of the SiO₂ with an average thickness of approximately 5 nm. FTIR, XRD and DSC are used to characterize the crystalline phase of the films, and it is found that compared with the pure PVDF films, doping with SiO₂ and dopamine@SiO₂ nanoparticles all increase the β-phase content of the composite film. SEM of the composite films shows that the dopamine@SiO₂ can be more uniformly dispersed in the PVDF matrix, and dopamine improves the compatibility of nano-SiO₂ and PVDF. The piezoelectric coefficient (d₃₃) and remnant polarization (P_r) of the SiO₂/PVDF and dopamine@SiO₂/PVDF composite films increase by up to 52%, 140%, 260% and 286% over that of the pure PVDF film, respectively. This work provides a promising new method for broadening nanofabrication technology and improving the performance of piezoelectric composites, contributing to studies on new curved-panel energy harvesters.