Highly Bendable and Durable Transparent Electromagnetic Interference Shielding Film Prepared by Wet Sintering of Silver Nanowires
journal contributionposted on 14.08.2018, 00:00 by Dong Gyu Kim, Jong Han Choi, Duck-Kyun Choi, Sang Woo Kim
Electromagnetic (EM) wave emissions from wearable or flexible smart display devices can cause product malfunction and have a detrimental effect on human health. Therefore, EM shielding strategies are becoming increasingly necessary. Consequently, herein, we prepared a transparent acrylic polymer-coated/reduced graphene oxide/silver nanowire (Ag NW) (A/RGO/SANW) EM interference (EMI) shielding film via liquid-to-vapor pressure-assisted wet sintering. The film exhibited enhanced Ag NW network formation and antireflection (AR) effects. The wet-sintered Ag NW shielding film had a threshold radius of curvature (ROC) of 0.31 mm at a film thickness of 100 μm, demonstrating its high flexibility, whereas the conventional indium tin oxide (ITO) shielding film had a threshold ROC of ∼5 mm. The EMI shielding effectiveness (SE) of the A/RGO/SANW multilayer film was approximately twice that of the ITO film at a similar relative transmittance (84–85%). The optical relative reflectance of the Ag NW layer was reduced due to the AR effect, and the visible-light transmittance was considerably improved owing to the different refractive indices in the multilayer shielding film. Because the acrylic coating layer had a high contact angle, the multilayer film exhibited high temperature and humidity durability with little change in the SE over 500 h at 85 °C and 85% relative humidity. The multilayer film comprising wet-sintered Ag NW exhibited high flexibility and humidity durability, high shielding performance (more than 24 dB at a relative transmittance of 85% or more), and high mass productivity, making it highly applicable for use as a transparent shielding material for future flexible devices.