Stretchable and Robust Silver Nanowire Composites on Transparent Butyl Rubber

Abstract

Silver nanowires (AgNWs) are leading materials for transparent conductive electrodes in optoelectronic devices. The solution processability of AgNWs combined with the optical transparency and electrical conductivity of solution-deposited AgNW networks makes them a promising alternative to conventional indium tin oxide. Furthermore, the ability of AgNW networks to withstand mechanical deformation means that AgNW networks may be the material of choice for next-generation flexible and stretchable optoelectronics. The drawback with the practical use of AgNWs, however, is that corrosion of AgNWs under ambient conditions damages the AgNW network and reduces the workable life span. Environmental degradation is especially problematic in stretchable electronics, which use elastomeric substrate materials that have a high gas permeability like poly(dimethylsiloxane) (PDMS). Covering individual AgNWs with a protective nanoscale coating to prevent corrosion complexifies their preparation and implementation in practical applications. This study presents an alternative approach in which the elastomeric substrate, transparent butyl rubber (TBR), acts as both a stretchable substrate and a protective gas barrier. TBR, an optically transparent formulation of poly(isobutylene-co-isoprene), is a synthetic rubber with an intrinsically low gas permeability. We demonstrate that AgNW networks embedded in a polyurethane adhesive and adhered to a TBR substrate provide high conductivity and optical transparency and are robust to tensile strain as well as extreme environments of humidified air, underwater storage, and corrosive acid vapors. We show that this system outperforms a comparison system that uses PDMS instead of TBR.