Simple and green fabrication process of nano silver conductive ink and the application in frequency selective surface.

A simple and green method for fabrication of nano silver conductive ink was developed for use in frequency selective surface (FSS). The hydrogen peroxide and ethyl cellulose were used as reducing agents and dispersants to synthesize silver nanoparticles (Ag NPs), and the ethyl cellulose was be used as binders of nano silver conductive ink eventually. The reaction byproducts of hydrogen peroxide are water and oxygen, the synthesized Ag NPs were be cleaned using purified water and alcohol without centrifugation and drying process. The conductive ink with 30 wt% silver content was formulated with the Ag NPs capped with ethyl cellulose, solvent and additive, the residual water and alcohol were be evaporated using vacuum distillation process. The prepared Ag NPs were characterized by SEM, XRD, TGA and FT-IR. The viscosity and surface tension of Ag NPs ink were tested, and the conductive ink was inkjet printed on Polyimide (PI) film to fabricate the FSS. The results showed the printed FSS had reflection resonances at 16.5 GHz and nulls deeper than the required -20 dB level, with depths of -32 dB.