One-step synthesis of Ag nanoparticles for fabricating highly conductive patterns using infrared sintering

Synthesizing metal nanoparticles (NPs) for conductive nano-ink applications on a large-scale and in a green, facile method is important. Here we use an ultrasonic-assisted method to synthesize Ag NPs with an average diameter of 15.5 +/- 1.0 nm in poly(N-vinylpyrrolidone) (PVP) solutions containing ascorbic acid (Vc) and glucose as mixed reducing agents. TEM, HR-TEM and XRD analysis confirmed the purity of Ag NPs. A thin, mixed Vc and PVP layer on the surface of the Ag NPs, confirmed by TGA and FT-IR, offered the air-stability of the Ag NPs. A rapid and effective sintering method was employed to obtain highly conductive patterns and avoid substrate damage. Upon sintering, the mixed layer quickly decomposed to obtain a highly conductive net. Infrared sintering at 15 W for <60 s was used to make conductive patterns whose resistivity reached up to 7.4 +/- 0.5 mu Omega cm, 4.6 times that of the bulk Ag. Three methods of the pattern designs were tested for conductivity and applicability. A sample paper-based electrode, RFID antenna, and our school logo were successfully printed and all exhibited good flexibility and conductivity. Both the synthesis and sintering process can be easily integrated into one machine, which is promising for future applications. (C) 2019 Tianjin university of technology. Published by Elsevier B.V.