Preparation of silver nanoparticles with hyperbranched polymers as a stabilizer for inkjet printing of flexible circuits

Abstract

In this paper, carboxyl-terminated hyperbranched polymer (CHBP)-stabilized silver nanoparticles (Ag NPs) were synthesized via chemical reduction in an aqueous phase and used to prepare a conductive ink that could be employed to fabricate conductive patterns via inkjet printing. The as-prepared CHBP-stabilized Ag NPs (CHBP-Ag NPs) were nearly uniform and monodisperse with a diameter of about 10–20 nm. The obtained CHBP-Ag NPs could be kept for several months in their solid form stably, which is convenient for transportation and storage. By simply dispersing CHBP-Ag NPs solid powder into ultrapure water, CHBP-Ag NPs aqueous ink could be obtained. And conductive patterns could be printed using the as-prepared CHBP-Ag NPs ink via a common color inkjet printer. Moreover, the printed patterns demonstrated a relatively low sheet resistance (1.31 Ω □⁻¹) under ambient conditions; after sintering at 180 °C, the sheet resistance could be further decreased to 0.16 Ω □⁻¹. The resistivity was 10.83 μΩ cm, which was about 7 times that of bulk silver (1.58 μΩ cm). Finally, the inkjet-printed conductive patterns were successfully integrated into an LED device circuit, indicating that the ink has great potential for application in flexible printed electronics.