Preparation And Stretching Stability Of Stretchable Transparent Conductive Films Based On Silver Nanowires

The development of flexible optoelectronic devices has further put forward the requirements for bendable and stretchable transparent conductive film(TCF).The silver nanowire(AgNW)percolating network produced by solution-based processes exhibits the most promising properties of high conductivity,transmittance and flexibility for replacing the rigid tin oxide(ITO)electrodes.However,due to the difference between the modulus of AgNW and flexible/stretchable transparent substrates and their weak interface force,AgNW is prone to slip or deviate from the substrate under mechanical deformation,especially tensile deformation,causing the conductivity of TCF to be destroyed.This work focuses on the preparation of a stretchable transparent conductive film based on AgNW.Through modifying the surface of transparent elastic substrates and adjusting the stretchable structure and performances of AgNW transparent conductive networks,the interface interaction between AgNW and the substrate is improved,and the TCF of high stretching stability was prepared while exploring the relationship between its structure and performance.To enhance the interface force between AgNW and the transparent elastic substrate of polydimethylsiloxane(PDMS),methods of plasma and chemical surface treatment were used to effectively improve the hydrophilicity of the substrate.It has been found that Poly(diallyldimethylammonium chloride)(PDDA)is the best candidate for PDMS surface modification.And by adjusting the concentration of the PDDA solution,the performance of the prepared AgNW-PDMS stretchable transparent conductive film can be improved.When the concentration is 1.5 mg/m L,the AgNW-PDMS film has a sheet resistance of 4.4 ?/sq,a transmittance of 82%,and a Fo M value of 408;and it has a stretching stability of 5% tensile strain,whose resistance change rate is about 7.7 after 100 cycles of stretching-recovery.It turns out that positively charged PDDA bonds to negatively charged AgNW and plasma-treated PDMS substrate through electrostatic interaction betweenElectrospinning technology was used to prepare polyvinylpyrrolidone(PVP)fiber network,and then AgNW was loaded on the fiber network by spraying coating method to prepare PDMSPVP-AgNW stretchable transparent conductive film(PPA STCF).Plasma surface treatment of PDMS substrate can effectively reduce the "coffee ring" effect without affecting the transmittance of PPA STCF;through plasma treatment for 10 min,the sheet resistance of PPA STCF is reduced from 11.8 ?/sq to 2.7 ?/sq while the transmittance remains ?66%.Research on the tensile property of PPA STCF showed that the resistance change rate after 100 cycles of stretching-recovery under 5% tensile strain was only 0.4;after 100 stretching cycles under 10%strain,the resistance change rate was 30.It shows that the PVP fiber network acts as an interface layer,which enhances the adhesion between AgNW and PDMS substrate and provides PPA STCF with stretching stability at 10% strain.Aiming to further improve the stretching conductivity stability of TCF,a polyurethane/polyvinylpyrrolidone composite elastic fiber network(ENF)was prepared using electrospinning technology,which was laminated with AgNW transparent conductive network to prepare PDMS-AgNW-ENF transparent conductive films(PAE STCF)with a sheet resistance of ? 5.6 ?/sq and a transmittance of ?60%.After 100 cycles of stretch-recovery at15% tensile strain,the resistance change rate of PAE STCF was 4,showing high stretching stability.The research shows that ENF network working as an intrinsic stretchable encapsulation layer can increase adhesion between AgNW and PDMS substrate,and then significantly reduce the sliding,fracture or shedding of AgNW during the stretching deformation.When PAE STCF was applied as a transparent film heater,the sample was heated to 60 °C within 100 s under 9 V input voltage and then remained stable,and shows quick response and temperature recoverability.