Preparation And Performance Of Biaxial Stretchable Conductive Nanocomposite

The stretchable conductor still has conductivity in the tensile and bending deformation,thus attracting the attention of academia and industry.At present,during the use of stretchable conductor,as the deformation increases,the resistance will increase dramatically,which greatly limits the application of elastic conductor.In order to solve the problem of increasing the resistance of elastic conductive materials under large deformation,a new process for the preparation of composite materials is proposed in this paper.With high elastic rubber as the basement layer,a conductive path is formed by adsorbing the conductive nanoparticles in a stretched state.The composite prepared by this method can retain the maximum extent of the conductive path under large deformation.At the same time,the conductivity of the composite may be further improved due to the denser concentration of the conductive particles in the free state.By changing the type of conductive particles,studying the effect of the conductive particle size and shape to conductivity and construction of conductive pathway,and a variety of composite materials prepared were characterized and researched the performance.By using LBL method,polyurethane(PU)aqueous solution is combined with gold or silver nanoparticles to form an elastic conductive material,and then character the composites.The results show that the conductivity of PU/Au nanoparticles composites is poor,and the resistance can be measured by so many layers.But the PU/Ag nanoparticles composites showed conductivity earlyier during the experiment and the resistance with increasing layers gradually become smaller.This is because the particle size(30nm)of silver nanoparticles is larger than that of gold nanoparticles(13nm).The larger particle size makes it easier to form a comductive path during the composite process,which makes the silver nanocomposite more conductive.This shows the great effect of particle size on the conductivity,so we used the one-dimentional and great aspect ratio MWCNT as conductive materials.PU/MWCNT composites exhibit electrical conductivity very quickly,and compared to PU/Ag nanocomposites,the number of LBL required for achieving the same conductivity is much less.In order to further improve the conductive properties of materials,we co-use the nanosilver solution and MWCNT dispersion.There are three methods: Two solutions were alternately adsorbed and deposited.Mechanical mixing of two solutions followed by adsorption and deposition.The silver nanoparticles were prepared by in-situ reduction method in MWCNT dispersion solution,and the resulting solution of silver modified MWCNT was used to adsorb and deposit.he experimental and characterizationresults show that PU/Ag-g-MWCNT composites had the best electrical properties,followed by PU/Ag/MWCNT composites,and PU/Ag-b-MWCNT composites were the worst.This is due to a mechanical mixture,the silver nanoparticles were not well dispersed around MWCNT,even becoming agglomeration.On the contrary,the silver modified MWCNT solution of silver nanoparticles were well dispersed in MWCNT around,increasing the contact area of the conductive path and reduces the contact resistance,so the conductivity is better.