Preparation Of Graphene-based Inks And Its Application In Inkjet Printing Flexible Circuits

Graphene has attracted tremendous attention since it was obtained in 2004 because of its excellent electric, mechanical, optical and thermal properties. Compared with traditional printing technology, Inkjet printing, which has less process steps, is suitable for mass production, and it can control the amount of deposited-material. So it becomes one of the most promising techniques for large-area fabrication of flexible electronics. How to print graphene-based flexible electrode via inkjet printing also has attracted more and more attention. In this paper, we used graphene oxide prepared by modified Hummers' method as the raw material to prepare graphene-based inks and printed flexible circuits. The details are given as follows:1. Graphene oxide prepared by modified Hummers' method was used as the raw material, and the relationship between concentration of graphene oxide and graphene oxide viscosity and surface tension has been studied. Also, we have investigated the effect of surfactants-sodium dodecyl sulfate(SDS) and Triton X-100 on the viscosity and the surface tension of inks, respectively. Ultimate, the graphene oxide(GO) inks which can be printed by HP-1010(household printer) were obtained. Then the GO inks were printed on polyimide(PI). The printed patterns could be reduced to flexible conductive patterns by three methods.2. The small size graphene oxide and graphene oxide were used as the raw material, and sodium dodecyl sulfate(SDS)was used as surfactant and dispersing agent. Then, graphene oxide was reduced by hydrazine hydrate and vitamin C, respectively. Eventually, the graphene inks were obtained and they had been used on PI. Final flexible conductive patterns were obtained by calcined at 400?.3. Silver nanoparticles and graphene oxide were mixed to prepare GO-Ag mixed dispersion. We investigated the effect of surfactants-sodium dodecyl sulfate(SDS) and Triton X-100 on the viscosity and the surface tension of inks, respectively. Eventually, the GO-Ag inks were obtained and they had been printed on PI. The printed patterns could be reduced to flexible conductive patterns by three methods.These results indicate that common printer can be used to fabricate various graphene-based devices in large scale. It is expected that the development of inkjet printable graphene-based inks will decrease the cost of the preparation of graphene electrode/circuits and open up new ways for the application of graphene-based thin film and patterns.