Mechano-Electrically Durability of Flexible Transparent Conductive Electrodes From Silver Nanowires/Polymer Nanocomposites

Abstract

This work presents conductive polymer composites to develop flexible, transparent, and highly deformable conductive electrodes. The nanocomposites elaborated in this study, based on silver nanowires dispersed in a polyurethane matrix, were obtained via a one-step spray coating process on a flexible PET substrate. A polyol-based synthesis combined with a nanowire screening process allows for the selection of nanowires with a very high aspect ratio (400). These high aspect ratio wires enable the conductive composite coatings (p_c = 1.3 vol.%) with a transmittance close to 70%. The confinement of high aspect ratio nanowires in a very thin composite layer facilitates a comparison between the increase in mechanical modulus and predictive behavior models for fiber-reinforced laminates. The mechanical reinforcement aspect ratio found by extrapolation exhibits the key role of the longest nanowires in mechanical properties. A homogenization limit has been identified at approximately 2.5 vol.% for this type of composite. Fatigue tests under bending conditions with a 3% strain and a 4 mm bending radius demonstrated that the surface resistivity (0.3 Ω/sq) remains stable after 1000 cycles.