In situ synthesis of silver nanowire gel and its super-elastic composite foams

Noble-metal aerogels (NMAs) including silver aerogels have drawn increasing attention because of their highly conductive networks, large surface areas, and abundant optically/catalytically active sites. However, the current approaches of fabricating silver aerogels are tedious and time-consuming. In this regard, it is highly desirable to develop a simple and effective method for preparing silver aerogels. Herein, we report a facile strategy to fabricate silver gels via the in situ synthesis of silver nanowires (AgNWs). The obtained AgNW aerogels show superior electrical conductivity, ultralow density, and good mechanical robustness. AgNW aerogels with a density of 24.3 mg cm^-3 display a conductivity of 2.1 × 10⁵ S m^-1 and a Young's modulus of 38.7 kPa. Furthermore, using an infiltration-air-drying-crosslinking technique, polydimethylsiloxane (PDMS) was introduced into 3 dimensional (3D) AgNW networks for preparing silver aerogel/elastomer composite materials. The obtained AgNW/PDMS aerogel composite exhibits outstanding elasticity while retaining excellent electrical conductivity. The fast piezoresistive response proves that the aerogel composite has a potential application for vibration sensors.