Development of a Gold Nanoparticle Dispersion for Plasma Jet Printing on Solid Substrates

Gold nanoparticles (AuNPs) were synthesised using ultrasonic spray pyrolysis (USP) with the addition of polyvinylpyrrolidone (PVP) as a stabilising agent and subsequently dried via lyophilisation. The resulting dried AuNPs were redispersed in ethanol, and homogenised to ensure uniform dispersion. This AuNPs` dispersion was then deposited onto a ceramic substrate (Al2O3) using plasma jet printing. Comprehensive characterisation of the dispersion, AuNPs and the resulting printed line were performed using: ICP-OES, SEM/TEM/EDS, UV-Vis, DLS, measurements of dispersion viscosity and printed line roughness. ICP-OES confirmed consistent gold content in the AuNPs` dispersion, while the SEM and EDS analyses revealed predominantly spherical AuNPs with minimal aggregation and similar size distributions. TEM, SAED, and STEM/EDS confirmed the crystalline structure and elemental composition of the AuNPs, with diverse morphologies and strong gold signals. The UV-VIS, DLS, and zeta potential measurements indicated moderate colloidal stability, and TGA verified the AuNPs dispersion’s composition. The AuNPs` dispersion exhibited thixotropic behaviour favourable for printing applications, while confocal microscopy confirmed smooth, uniform printed traces, with an average surface line roughness of 1.65 µm. The successful use of plasma printing with the AuNPs` dispersion highlights its potential for functional material applications in electronics.