Plastic Deformation Of Silver Nanowires And Application In Transparent Conductive Films

Silver nanowires has widely application in many fields such as transparent electrodes,electrocatalysis,nanodevices and conductive adhesives due to their excellent performance.The melting point of metal material will decrease after being nanometer scale,this phenomenon will effect the thermal stability of the silver nanowires.Up to present,there haven't any reports about the thermal stability and plastic deformation of silver nanowires.Based on the thermal stability of silver nanowires,the ultrasonic pressure processing technology is introduced into the plastic deformation research of silver nanowires.The thermal stability of silver nanowires with an average length of 30?m and a diameter of 50 nm was studied.The DSC test results showed that silver nanowires has four endothermic peaks respectively in 220?,330?,450? and 960?.Then analyzing the morphology of silver nanowires in high temperature,the silver nanowires begin to melt in 200?,intensify melting and begin spheroidization with the temperature increased,and melted into micron silver particles in 450?.Silver nanowires first melted after being heated,because of its special "bamboo-like" growth mode,the "bamboo festival" is a weak area of silver nanowires.Therefore,silver nanowires will have a fuse failure when it is above 200?.The silver nanowires would occur plastic deformation and change into silver nanobelts under ultrasonic pressure processing.And the phenomenon of ductility and work hardening would come out with plastic deformation,which is same with conventional silver.In this process,the product of the ultrasonic sounding time and the pressure value is regarded as the "input energy".The amount of silver nanobelts stretch would increase with the increase of "input energy",become the same value under the "input energy".For example,the stretching ratio can reach 70% when the "input energy" is 0.36 MPa.S.And the "bamboo-like" part of the silver would break with the increase of the "input energy".The hardness of silver nanobelts would increase with the increase of plastic deformation by the characterized of atomic force microscopy.After comparing the changes hardness and stretching ratio of silver nanobelts,we found that the result of hardening were basically same under the same degree of deformation.After introducing the ultrasonic pressure process into the preparation of the silver nanowires transparent conductive films,we found the silver nanowires can be effectively connected,the conductivity of silver nanowires would improve with the decrease of the node resistance.For instance,a silver nanowires transparent conductive film with 11% silver nanowires surface coverage had 90% transmittance,0.9% haze and 35 ?/? sheet resistance after being ultrasonic pressure processed with an "input energy" of 0.03 MPa.S.The transmittance decreased by 1%,the haze reduced by 28%,and the conductivity increased by 50% comparing with the conductive film without any process.The silver nanowires conductive network forms a nested structure with the substrate,and is stably embedded into the matrix after processed,and would have strong adhesion between the conductive layer and the substrate.The bending experiment results show that the processed conductive film had a better bending resistance than the unprocessed transparent conductive film.