Construction Of Hybrid Conductive Network Based On Copper Nanowires And Its Application In Flexible Electronic Materials

With the rapid development of flexible electronic materials and sensing technology,flexible wearable sensors play an important role in human motion monitoring.The human body's full-range monitoring usually requires the flexible strain sensors to have both large sensing range and high sensitivity,but these two parameters are mutually exclusive,thus the design of reasonable conductive building blocks and network structure to solve the above-mentioned contradiction is an important way to obtain high-performance sensor.Among a myriad of conductive fillers for sensors,copper nanowires?Cu NWs?have excellent photoelectric performance,mechanical flexibility,thermal performance and low price,making them the most promising sensing materials in the flexible sensors.However,Cu NWs are easy to be oxidized at room temperature,which reduces its electrical performance and limits its application in flexible sensors.The purpose of this work is to develop a novel and simple method to prepare Cu NWs with controllable structure and high antioxidant capacity and conductive networks with controllable structure are constructed based on Cu NWs,which are composited with elastic polymers,yielding highly sensitive and stretchable sensors.The main research contents are as follows:?1?Firstly,Cu NWs was synthesized by a hydrothermal method.Core-shell Cu-Ag NWs was successfully prepared by a simple and controllable galvanic replacement reaction between Cu NWs and Ag?NH₃?₂⁺,and the effect of Ag⁺content on the structure and properties of Cu-Ag NWs was also investigated.Through a series characterization of Cu-Ag NWs the antioxidant performance was the best when the mass ratio of Cu NWs to Ag⁺was 8:6.Inspired by the structure of nature nacre,we prepared a flexible sensor of“brick and mortar”nacre-mimetic architecture with Cu-Ag NWs/rGO as conductive“brick”and SBS as flexible“mortar”.The sensor has a large sensing range?up to 374%strain?and high sensitivity?a gauge factor up to 87362?,and can monitor the movement of human fingers,wrists and knees.?2?Secondly,we synthesized polypyrrole-coated Cu NWs?Cu@PPy NWs?by a new one-step method,and the effect of pyrrole content on the morphologies and oxidation resistance of Cu@PPy NWs was further studied.When the mass ratio of Cu²⁺and pyrrole was1:1,the antioxidant performance of Cu@PPy NWs was the best.Cu@PPy NWs/Ag NFs hybrid conductive network was assembled by vacuum filtration and embedded into SBS matrix to prepare a flexible strain sensor with cluster structure.The fracture sensing mechanism,crack-propagation mechanism and slippage sensing mechanism combined with the dual bridge function of Ag NFs and Cu@PPy NWs,make it have a large sensing range?up to 185%strain?and ultra-high sensitivity?GF=1.22×10⁶?.This composite material can be used to monitor the omnidirectional movement of human body and the connect light-emitting diodes.