A PEDOT:PSS-based Elastic Conductive Composite And Its Application

Elastic conductive composite is a material capable of maintaining electronic performance under various mechanical deformations.In recent years,With the acceleration of world informatization and the development of the Internet of Things,the demand for high-performance and easy-to-process elastic conductive composite materials is gradually increasing.As a typical polymer conductor,poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)has attracted much attention due to its unique polymer structure and tunability.It is often used as an electronic substrate for elastic conductive composites.This subject proposed a simple and efficient method to prepare PEDOT:PSS-based elastic conductive composites.It reveals the mechanism of doping on the electrical and mechanical properties of elastic conductive composites and its applications in tensile interconnection,wearable stress sensors,and screen printing processes.The results of the study are as follows:(1)The polar solvent ethylene glycol(EG)was used as a "secondary dopant",and Triton X-100 was used as a "tertiary dopant" to dope PEDOT:PSS so that it could be mixed with polydimethylsiloxane(PDMS).We found that the introduction of Triton X-100 can effectively relieve the interfacial tension between the two phases,and there is no significant particle deposition on the surface of the film after curing.Microscopic analysis shows that both dopants can promote the conformational transition of PEDOT segments from benzene to quinone structure in PEDOT:PSS,and further improve the electrical properties of the composite.In terms of mechanical properties,Triton X-100 plays a major role in reducing the tensile modulus of the composite,which is manifested in easier stretching and increase in elongation at break,and the maximum effective strain can reach about 95%.Combined with the analysis of electrical measurement results,after 7 wt%EG and 10 wt%Triton X-100 doping,the composite material can obtain a square resistance of 20 ?/sq and a tensile strain of 82%.(2)Under the optimal doping ratio,increasing the concentration of PEDOT:PSS can improve the conductivity of the film,but it will also reduce the mechanical properties and transmittance of the film.XRD,SEM,UV-vis and physical performance analysis show that the film containing 20 wt%PEDOT:PSS not only shows good conductivity,recoverability and piezoresistive effect,but also has excellent tensile properties and transparency and cyclic stability.The GF value of the film can be increased from 3.25 at 40%strain to 12.5 at 120%strain,and can reach 17.1 at the maximum strain.(3)By connecting the elastic conductive composite film with the LED in series,the ?-?response test shows that the LEDs are lit at the rated voltage,showing a stable slope of current growth,and the LED lamp has no obvious brightness change under different external forces;As a wearable stress sensor,it can effectively monitor various joint movements of the human body in real time;In addition,the composites exhibited satisfactory screen-printing suitability,with no noticeable loss of detail and performance failure in the printing effect.