Controllable synthesis and sintering of silver nanoparticles for inkjet-printed flexible electronics

An effective and facile strategy was developed to successfully synthesize nearly uniform silver nanoparticles (AgNPs) with particle size of <10 nm, and demonstrated to achieve the sintering of AgNPs at room temperature for inkjet-printed flexible electronics. In such system, a series of different chain-length alkylamines were exploited as capped molecules to controllable synthesis of uniform AgNPs with the mean nanoparticle size in rang of 8.6 +/- 0.9, 8.9 +/- 1.2 and 9.2 +/- 1.6 nm, and these ultra-small nanoparticles were very favorable to attain an excellent printing fluency. Based on the as-synthesized AgNPs, a sequence of flexible electrocircuits was successfully fabricated by ink-jet printing technique. After the dipped treatment, the printed AgNPs were achieved to spontaneous coalescence and aggregation at room temperature induced by preferential dissolution of capped molecules on AgNPs surfaces into methanol solution. These aggregated AgNPs demonstrated superior controllability, excellent stability and low resistivity in the range of 31.6-26.5 mu Omega cm, and would have enormous potential in the application to be tailored for assembly of optoelectronics devices. (C) 2015 Elsevier B.V. All rights reserved.