Highly Bendable and Durable Transparent Electromagnetic Interference Shielding Film Prepared by Wet Sintering of Silver Nanowires

Abstract

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.

Double-layer metal mesh etched by femtosecond laser for high-performance electromagnetic interference shielding window

“…The development of transparent EMI shielding materials is imperative, but the existing great challenge is how to balance the inherent contradiction between the high optical transmittance and the strong shielding efficiency. [4][5][6][7][8] Tremendous efforts have been committed to achieving transparent EMI shielding using a number of strategies and a variety of materials, including transparent conductive oxide, ultra-thin metal lms, various shapes of metal grids with micro periods, bandpass frequency selective surface, silver nanowire, graphene and other carbon-based materials. [9][10][11][12][13][14] Among them, indium tin oxide (ITO) is currently used in transparent coating, exhibiting excellent visible light transmittance and strong electromagnetic shielding efficiency.…”

Extremely Robust and Reliable Transparent Silver Nanowire‐Mesh Electrode with Multifunctional Optoelectronic Performance through Selective Laser Nanowelding for Flexible Smart Devices

“…[14,15] Increasing the density of Ag NWs to increase the contact area can increase the bending durability; however, this approach significantly degrades the optical properties. To solve this problem, attempts have been made to enhance bending durability by improving the network of NWs through physical [15][16][17][18][19][20][21] or chemical bonding. [22][23][24] Choi et al [15] fabricated sintered Ag NWs with enhanced networking by bonding NWs using roll-to-roll wet sinter forging.…”

Flexible and transparent graphene/silver-nanowires composite film for high electromagnetic interference shielding effectiveness

“…In the past decades, the flexible transparent conductive films, which are made by adding appropriate content of conductive components, such as carbon nanotubes (CNTs) [15][16][17][18][19][20], silver nanowires (AgNWs), and metal mesh, into the polymer film matrix [21,22], have raised great attention in flexible electronics and EMI shielding field [23]. For example, Umrao et al [24] reported that CNTs films achieved both high EMI SE and light transmittance, but the large-scale production with high uniformity is littered with challenges [25,26].…”

“…Han et al [39] used a combination of GNS and metal mesh structure to make a film, and the EMI SE was 14.1 dB in the 12-18 GHz when the light transmittance was 90.5%. Kim et al [23] fabricated the polymer-coated/reduced graphene oxide/silver nanowires with an EMI SE of 24.1 dB in 0.5-3 GHz and a light transmittance of 82.5%. Ma et al [40] fabricated a polymethyl methacrylate (PMMA)/graphene/metal mesh hybrid film with the EMI SE of up to 28.9 dB at 12-18 GHz when the light transmittance was 91%.…”