Mechanically Robust Magnetic Fe₃O₄ Nanoparticle/Polyvinylidene Fluoride Composite Nanofiber and Its Application in a Triboelectric Nanogenerator

Mechanically robust composite nanofibers (NFs) with enhanced magnetic properties were made from polyvinylidene fluoride (PVDF) and Fe₃O₄ nanoparticles (NPs) by an electrospinning method. At up to 11.3 wt %, Fe₃O₄ NPs were embedded randomly in the PVDF NFs, but when the content exceeded 17 wt %, the NPs aggregated on the NF surfaces. Magnetization of the composite NFs consistently increased with the increasing Fe₃O₄ NP content. The mechanical strength of the Fe₃O₄ NP/PVDF composite NF was enhanced by a dispersion strengthening mechanism. A triboelectric nanogenerator was made from the composite, which showed enhanced output performance with the Fe₃O₄ NP content less than 11.3 wt %, but the performance degraded at higher content. These results were attributed to the electret doping effect and surface aggregation of the Fe₃O₄ NPs on the NFs, respectively.