Investigation of Morphology and EMI Shielding Efficiency of Cotton Fabrics Functionalized with rGO and rGO–REVO₄ (RE =Sm, Nd, Dy, Gd) Nanoparticles for Advanced Wearable Applications

The increasing number of electronic devices and the development of telecommunication and wireless communication have increased the density of secondary non-ionizing waves and created electromagnetic wave pollution. To prevent their impact, electromagnetic interference (EMI) shielding materials are used. Due to physico-chemical properties, such as lightweight, chemical stability and tunable electrical properties, graphene and its derivate, graphene oxide (GO), seem to be a smart alternative. Its flexibility, biocompatibility, and sheet-like morphology make it particularly attractive for functionalization of textile fabrics. This paper presents innovative functionalized cotton fabrics modified with an agent-free approach using reduced GO (rGO) and rare-earth-based nanoparticles (REVO4: SmVO4, GdVO4, NdVO4, DyVO4). Cotton was functionalized with GO and REVO4 by repeating dipping, drying, and reduction cycles, from 1 to 30. Scanning electron microscopy (SEM) proved that GO sheets were homogeneously covering cotton fibers, while small spherical objects were identified across the fibers and confirmed REVO4 deposition. The effectiveness of EMI shielding in the samples with the highest number of deposited GO and REVO4 layers was between 20 and 28% across the band 2.60 to 3.95 GHz frequency range. Although shielding effectiveness is limited, the results highlight the potential of rGO and rare-earth-based nanoparticles as promising candidates in the professional clothing of workers in radar and telecommunications.