Preparation And Properties Of PDMS Nanofiber Film-based Triboelectric Nanogenerators

With the rapid development of flexible electronics and Internet of Things technology,flexible wearable electronics have a wide range of applications in emerging fields such as health monitoring,human-computer interaction,and prosthetics.In order to enhance the portability and comfort of flexible wearable electronics,the development of flexible power sources with easy integration and low maintenance cost is becoming a hot research topic.Triboelectric nanogenerator(TENG)can effectively harvest random mechanical energy in the environment and convert it into electrical energy,showing a promising application in the field of flexible wearable electronics as a micro/nano power source and self-powered sensor.The output performance of TENG is proportional to the square of the surface charge density of the friction material,so it is important to prepare high frictional electric materials to build high performance flexible TENGs.In this paper,positive frictional electric material based on Poly(ε-caprolactone)(PCL)nanofiber film and negative frictional electric material based on polydimethylsiloxane(PDMS)nanofiber film are prepared by electrostatic spinning process,and the prepared nanofiber films are used as friction layers to construct single-electrode TENGs,which are tested and discussed.The specific studies are as follows:(1)Construction and performance investigation of single-electrode flexible TENG based on PDMS nanofiber film.Firstly,polyvinyl pyrrolidone(PVP)/PDMS shell-core structured nanofiber film is prepared by two-component coaxial electrostatic spinning technique,and the PVP in this spun fiber film is removed by soaking in ethanol to finally obtain pure PDMS nanofiber film.The PCL nanofiber film is also prepared by electrostatic spinning,and it is used as a positive friction material to construct a single-electrode flexible TENG with PDMS nanofiber film.The TENG exhibits good electrical output performance with an open-circuit voltage of 130 V,a short-circuit current of 2.4 μA,and a transferred charge of 48 n C at the frequency of 1 Hz,and the generates instantaneous power under the condition of the best matching resistance of 50 MΩ.This PDMS nanofibers-based flexible TENG as a micro/nano power source is capable of harvesting mechanical energy from human motion to light LEDs as well as charge commercial capacitors.(2)To further enhance the output performance of PDMS nanofibers-based flexible TENG,MXene nanosheets as charge trapping layer are doped into PDMS nanofibers.The MXene nanosheets are prepared by the in situ generation of HF from Li F/HCl,and then PDMS/MXene nanofiber film is also prepared by coaxial electrostatic spinning.PCL nanofiber film as an active layer and PDMS/MXene nanofiber film are used to construct a single electrode PDMS/MXene nanofibers-based TENG.The open-circuit voltage,shortcircuit current,and transferred charge of this TENG are increased by 24%,38%,and 33%compared with pure PDMS nanofibers-based TENG,respectively.The PDMS nanofibers-based TENG explored in this thesis is expected to serve as a flexible power supply unit for flexible wearable electronic devices.