Study On The Preparation,Performance And Application Of Rubber/graphene Electrically Conductive Composites

With the booming development of wearable electronics,flexible strain sensors based on electrically conductive rubber composites have drawn widespread consideration.For electrically conductive rubber composites,graphene(GE)is an ideal filler due to its extraordinary electrical conductivity and large specific surface area.Rubber/GE composites filled with a large amount of GE may attain a high electrical conductivity.However,high filler loadings would increase the cost and deteriorate other properties of rubber composites,such as the sensing properties.In this study,polyurethane(PU)sponge was adopted as the template to absorb graphene oxide(GO)dispersions.The graphene foam(GF)was prepared through a facile ethonal flame treatment process by which the reduction of GO and the pyrolysis of PU were completed synchronously.Furthermore,the natural rubber(NR)/GF composites were fabricated by a casting strategy.The effects of number of times absorbing GO was performed and the pore size of PU template on the electrical conductivity and strain sensing performance of NR/GF composites were studied in detail.The results showed that with an increase in the number of times absorbing GO was performed,the electrical conductivity of NR/GF composites increased,while the strain sensitivity decreased.Particularly,with loading 0.2 wt.%GF,the electrical conductivity of NR/GF composites achieved 0.1 S/m.With the decrease of the pore size of PU template,the NR/GF composites presented a decreasing tendency in both electrical conductivity and strain sensitivity.In addition,NR/GF composites were used as flexible stain sensors for monitoring footstep,finger bending and pronouncing,etc.Cotton bandage was employed as the template to absorb GO dispersions.The two-dimensional graphene mesh(GM)was prepared through an ethonal flame treatment process.Subsequently,the NR/GM composites were fabricated.The effects of number of times absorbing GO was performed on the electrical conductivity and strain sensing performance of NR/GM composites were investigated.The results showed that with an increase in the number of times absorbing GO was performed,both the electrical conductivity and strain sensitivity of NR/GM composites increased.When the adsorption of GO was conducted for 3 times,the NR/GM composites showed the optimum comprehensive performance in strain sensing.NR/GM composites were further used as flexible sensors with the advantages of high sensitivity,large strain sensing range,superb signal stability,etc.This study also demonstrated the capability of these sensors for detection of full-range human activities,indicating their broad application prospects in the field of artificial intelligence,and so forth.