Mono‐disperse submicron silver powder for conductive elastomer

Abstract The synthesis of superfine silver powder with good dispersity is of great significance for accelerating the development of high‐end electronics and photovoltaic products. Herein, a kind of quasi‐spherical submicron silver powder prepared by the introduction of gelatin during silver ions reduction is reported. The optimal scheme is determined that the initial pH of gelatin solution is 3 and the mass of gelatin ( M _w 50,000—70,000) is 10% of silver nitrate, leading to a mono‐disperse silver powder with regular morphology and average particle size of 0.5 µm. In addition, the prepared silver powder can be further combined with polydimethylsiloxane (PDMS) to form a stretchable conductive elastomer (PDMS/Ag elastomer). In unstretched state, the minimum sheet resistance of the elastomer can reach 66 Ω/□ without annealing treatment. Even when the elongation reaches 100%, it still exhibits good conductivity with a sheet resistance of only 13 kΩ/□. The comprehensive performance, mainly referring to stretching and conductivity, is comparable to that of some flexible conductive materials involving silver nanowire or nanocarbon. Thus, this study will demonstrate a new class of silver powder with a potential in flexible electronics.