GO-AgNWs free-standing composite films for microwave electromagnetic interference shielding

Abstract

The ongoing progress in communications, broadcasting systems, and the electronic industry results in increased exposure to electromagnetic interference (EMI). The proliferation of electromagnetic waves pollution is attributed to the extensive use of electronic devices like mobile phones, Wi-Fi, and microwave ovens in everyday activities [1, 2]. The risk of EMI is especially highlighted for individuals with implanted active medical devices or profesionals working in close contact to this type of irradiation. EMI shielding materials with 30 dB shielding efficiency are deemed appropriate for commercial applications based on references. Therefore, there is a strong need for lightweight, elastic, stretchy, transparent, robust, and highly efficient shielding materials that are appropriate for textile manufacturing and equipment covering. Presented work investigated composite materials made of graphene oxides (GO) [3] and silver nanowires (AgNWs) and their effectivenes as EMI shielding materials. Composites were generated from GO with sheet sizes ranging from 150 to 2000 nm and flake thicknesses between 2 and 5 nm. The average thickness of the free-standing films was approximately 14.8 μm. The ratio of these nanomaterials was analysed to adjust the shielding effectiveness throughout a wide microwave frequency range up to 18 GHz. A shielding effectiveness of around 6.5 dB was recorded for the r-GO free-standing film.