Gold Inks for Inkjet Printing on Photo Paper: Complementary Characterisation.

Nowadays, cost-effective, available, and flexible paper-based electronics play an essential role in the electronics industry. Herein, we present gold nanoparticles (AuNPs) as a potential raw material for gold inks in the future for such purposes. AuNPs in this research were synthesised using the ultrasonic spray pyrolysis (USP) technique from two precursors: gold (III) chloride tetrahydrate and gold (III) acetate. Synthesised AuNPs were collected in a suspension composed of deionised (D.I.) water and the stabiliser polyvinylpyrrolidone (PVP). AuNPs' suspensions were subjected to the rotavapor process to obtain gold inks with higher Au concentration (>300 ppm). ICP-MS measurements, the size and shape of AuNPs, ζ-potential, Ultraviolet-visible (UV-Vis) spectrophotometry measurements, and scanning electron microscop y (SEM) of gold inks were carried out in order to find the optimal printing parameters. In the final stage, the optical contact angle measurements were performed using a set of polar to non-polar liquids, allowing for the determination of the surface free energy of gold inks. Inkjet printing of gold inks as defined stripes on photo paper were tested, based on the characterisation results.