Preparation Of Flexible Braided Nanogenerator By Conjugated Electrostatic Spinning

With the acceleration of the modern "intelligent" society,the development of intelligent wearable textiles has made rapid progress.However,flexible,portable and sustainable micro-power supply systems remain a challenge for smart electronic devices.Nanogenerator(NG)is an emerging energy harvesting device that offers a way to work sustainably without an external power source.In this paper,continuous core-spun yarns have been prepared by conjugation electrospinning technique with copolymer P(VDF-Tr FE)of N,N-dimethylformamide(DMF),acetone and polyvinylidene fluoride(PVDF).Flexible silica yarns were prepared from Polyvinyl alcohol(PVA)and TEOS,and the two yarns were further woven into fabrics respectively.The morphology,mechanics and properties of fabric nanogenerator of continuous nanofiber yarns were systematically studied.The research contents are as follows:Cu/P(VDF-TrFe)nanofiber yarns were prepared by conjugation electrostatic spinning with P(VDF-Tr Fe)-DMF-acetone blending system.The effects of different spinning voltage,copper core diameter,fabric structure and piezoelectric frequency on the morphology and structure of nanofiber yarns and the performance of nanogenerator were studied.The experimental results show that: Using 20.0wt % concentration of P(VDF-Tr Fe)spinning solution,0.02 mm diameter copper fiber as core electrode,spinning voltage 14.0 k V,distance between two nozzles 15 cm,distance between needle and collecting cylinder about 18 ± 2 cm,the yarn prepared has good flexibility and mechanical properties.The Cu/P(VDF-Tr Fe)fabric nanogenerator weaved by this kind of yarn shows good flexibility,permeability,mechanical stability and working ability after running continuously for 60 min or washing.A 4 cm × 4 cm fabric can produce a current of 38 nA and a voltage of 2.7 V at 15 N.In order to be more environmentally friendly and improve the performance of nanogenerators,flexible inorganic silica yarns were prepared by using PVA and TEOS as raw materials.The effects of different voltage,calcination temperature,twisting rate and other parameters on the morphology,structure and performance of nanofibers were studied.The experimental results showed that the spinning voltage was 9.0 k V,the distance between the two nozzles was 13 cm,and the distance between the needle and the collecting cylinder was about 8cm.The yarn prepared was uniform and had good flexibility after calcination.Compared to the traditional inorganic friction nanogenerator which is hard and cannot bend,the inorganic fabric nanogenerator composed of this yarn has ideal super flexibility(bending more than 180).The friction between a 2.7 cm 2.7 cm fabric and a P(VDF-Tr FE)material can produce a current of400 nA and a voltage of 75 V at a frequency of 1 Hz.