Highly\nBendable and Durable Transparent Electromagnetic Interference Shielding\nFilm Prepared by Wet Sintering of Silver Nanowires

Abstract

Electromagnetic\n(EM) wave emissions from wearable or flexible smart display devices\ncan cause product malfunction and have a detrimental effect on human\nhealth. Therefore, EM shielding strategies are becoming increasingly\nnecessary. Consequently, herein, we prepared a transparent acrylic\npolymer-coated/reduced graphene oxide/silver nanowire (Ag NW) (A/RGO/SANW)\nEM interference (EMI) shielding film via liquid-to-vapor pressure-assisted\nwet sintering. The film exhibited enhanced Ag NW network formation\nand antireflection (AR) effects. The wet-sintered Ag NW shielding\nfilm had a threshold radius of curvature (ROC) of 0.31 mm at a film\nthickness of 100 μm, demonstrating its high flexibility, whereas\nthe conventional indium tin oxide (ITO) shielding film had a threshold\nROC of ∼5 mm. The EMI shielding effectiveness (SE) of the A/RGO/SANW\nmultilayer film was approximately twice that of the ITO film at a\nsimilar relative transmittance (84–85%). The optical relative\nreflectance of the Ag NW layer was reduced due to the AR effect, and\nthe visible-light transmittance was considerably improved owing to\nthe different refractive indices in the multilayer shielding film.\nBecause the acrylic coating layer had a high contact angle, the multilayer\nfilm exhibited high temperature and humidity durability with little\nchange in the SE over 500 h at 85 °C and 85% relative humidity.\nThe multilayer film comprising wet-sintered Ag NW exhibited high flexibility\nand humidity durability, high shielding performance (more than 24\ndB at a relative transmittance of 85% or more), and high mass productivity,\nmaking it highly applicable for use as a transparent shielding material\nfor future flexible devices.