Water-based ultraviolet curable conductive inkjet ink containing silver nano-colloids for flexible electronics

In this study, we demonstrate a simple approach of fabricating conductive ultraviolet curable (UV) inkjet ink composed of silver nano-colloids and water-based UV resin. A type of stable silver nano-colloids with uniform size is prepared by oxidation–reduction reaction and polymer-coating process in a mixed aqueous solution of silver nitrate, glucose, triethylamine and poly (vinyl pyrrolidone). The results show that concentration of silver nitrate and glucose, the amount of glucose and the input rate of triethylamine have different effect on the shapes and sizes of the products. An environment friendly UV conductive inkjet ink is further produced by adding water-based UV resin and photo-initiator into nano-colloids. A conductive pattern can then be achieved by the following steps: ink-jet printing UV conductive ink on flexible polyimide substrate, evaporation of water on heating stage, curing under UV spot light source and sintering in muffle furnace. The effect of different silver content, thickness of conductive pattern and sintering temperature on the conductivity performance are investigated in detail. These novel composites studied here have a great potential application for flexible photonics and electronics.