Preparation And Properties Of Graphene Conductive Paste Based On Fabric Printing

As a new two-dimensional carbon material,graphene has attracted much attention due to its unique chemical structure and excellent electrical,thermal and mechanical properties.It has great potential applications in many fields.A more common method for preparing graphene conductive fabrics is dip coating,but this method often requires repeated finishing,and the process is cumbersome.The graphene conductive paste can be directly printed onto the fabric to obtain a graphene conductive fabric,which imparts excellent electrical conductivity to the fabric,and can also be used to print fine conductive circuits on the fabric.Graphene oxide/waterborne polyurethane(GO/WPU)conductive paste was prepared by solution blending graphene oxide dispersion and waterborne polyurethane.It was printed on the cotton fabric by screen printing,and then the graphene oxide was reduced by the insurance powder to obtain a reduced graphene oxide/waterborne polyurethane(RGO/WPU)conductive paste printed fabric.The increase in the C/O ratio from 2.92 to 3.55 in the XPS results demonstrated the effectiveness of reduction.In the SEM image,it could be seen that GO and WPU were uniformly distributed on the surface of the fiber without significant agglomeration.The GO/WPU conductive paste was a pseudoplastic fluid that could be used to print fine patterns.After reduction,the unit length resistance of GO/WPU 1.2% conductive paste printed 1,2,3,4,5 mm line width circuits were 29.1,20.9,17.3,14.1,10.8 M?/cm,respectively.The UV transmittance of RGO/WPU conductive paste printed fabrics did not exceed 5%,and decreased with the increase of graphene oxide,indicating that they all have excellent UV protection ability.The UV protection factor(UPF value)of RGO/WPU 1.2%conductive paste printed fabric was 757,which was 98 times than control cotton fabric.The K/S value of RGO/WPU conductive paste printed fabric increased with the increase of graphene oxide.Although the dry and wet rubbing fastness of printed fabric decreased with the increase of graphene oxide,they all showed excellent Washable performance,up to 4-5and 5 levels.The microwave thermal expansion graphene(G)was prepared and then formed polyaniline(PANI)on its surface by in situ polymerization.The G/PANI conductive paste was prepared by centrifugation and printed on a polyester fabric to obtain a G/PANI conductive paste printed fabric.It could be seen in the SEM image that there were many PANI small particles on the G surface.G/PANI conductive pastes were pseudoplastic fluids that could be printed with fine patterns.The conductivity of G/PANI conductive paste increased with the increase of G content in the system.G/PANI 25 conductive paste printed fabric showed the best conductivity and the sheet resistance is 0.6 k?/sq.Conductive circuits with line widths of1,2,3,4,and 5 mm were printed by G/PANI 25 conductive paste,It was found that the resistance per unit length of the conductive circuit decreased with the increase of line width,which was 2495.1,1132.5,836.2,558.7,418.7 ?/cm.respectively.High concentration graphene oxide was directly printed on the cotton fabric,and then immersed into silver ammonia solution.Graphene oxide and the silver ions adsorbed thereon are simultaneously reduced by L-ascorbic acid to prepare a reduced graphene oxide-silverconductive fabric(Cotton-RGO-Ag).The group and crystal structure of Cotton-RGO-Ag were analyzed by FTIR and XRD.The reduction degree of graphene oxide in Cotton-RGO-Ag was characterized by Raman and XPS.The concentration of silver nitrate in the silver ammonia solution,the immersion time and graphene oxide printed times showed a great influence on the conductivity of conductive circuit.When the concentration of silver nitrate in the silver ammonia solution was 10 mg/mL,the immersion time was 15 min,graphene oxide printed times was 12,the sheet resistance of the conductive circuit was3.6 ?/sq.Conductive circuits with line widths of 1,2,3,4,5 mm preparaed along the warp,weft and diagonal directions of the fabric,The unit length resistance increaseed as the line width became smaller.When the line width was 5 mm,the unit length resistance were 3.2,3.6,2.2 ?/cm,respectively.