Enhancement of Piezoelectric Properties of Flexible Nanofibrous Membranes by Hierarchical Structures and Nanoparticles

Abstract

Piezoelectric nanogenerators (PENGs) show superiority in self-powered energy converters and wearable electronics. However, the low power output and ineffective transformation of mechanical energy into electric energy l limit the role of PENGs in energy conversion and storage devices, especially in fiber-based wearable electronics. Here, a PAN-PVDF/ZnO PENG with a hierarchical structure was designed through electrospinning and a hydrothermal reaction. Compared with other polymer nanofibers, the PAN-PVDF/ZnO nanocomposites not only showed two distinctive diameter distributions of uniform nanofibers, but also the complete coverage and embedment of ZnO nanorods, which brought about major improvements in both mechanical and piezoelectric properties. Additionally, a simple but effective method to integrate the inorganic nanoparticles into different polymers and regulate the hierarchical structure by altering the types of polymers, concentrations of spinning solutions, and growth conditions of nanoparticles is presented. Further, the designed P-PVDF/ZnO PENG was demonstrated as an energy generator to successfully power nine commercial LEDs. Thus, this approach reveals the critical role of hierarchical structures and processing technology in the development of high-performance piezoelectric nanomaterials.

Polyvinylidene Fluoride/Aromatic Hyperbranched Polyester of Third-Generation-Based Electrospun Nanofiber as a Self-Powered Triboelectric Nanogenerator for Wearable Energy Harvesting and Health Monitoring Applications

“…Similarly, the interfacial interactions of Ar.HBP-3 can pull PVDF link chains to form crystals on the surface in an all-trans form, thereby enabling the conversion of localized non-polar α -phase to polar β -phase. Ar.HBP-3 serves as a nucleating agent in this circumstance, offering basic units for the creation of PVDF crystalline polymerization and inciting the creation of PVDF’s β -phase fragment through potent interaction at the interface [ 28 , 56 ]. In contrast, the interfacial interactions and polarity of –CH 2 /–CF 2 dipoles differ.…”

“…It is claimed that, in comparison with its as-cast film, PVDF nanofibers produced by the electrospinning technique exhibit a greater coefficient of piezoelectricity and higher energy conversion efficiency [ 5 , 6 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ]. Some of the positive outcomes of obtaining electrospun fibers are higher surface area-to-volume ratio, availability of diversified polymeric materials, combination of the materials’ flexibilities, comparatively lesser manufacturing expenses and ease in depositing fibers on various types of substrates [ 52 , 53 , 54 , 55 , 56 , 57 , 58 ].…”