Dr. Svetlana Jovanović

While sources of non-ionizing radiation are becoming dense, new materials able to prevent their propagation are not developing at the same dynamic, but are significantly lagging. This trend is particularly noticeable in the field of textile fibers. Specifically, the development of fabrics designed for professional exposure to non-ionizing radiation across various electromagnetic frequency ranges is insufficient, and the number of products available on the market is limited. Although many materials are currently being studied for non-ionizing radiation blocking and EMI shielding, nanomaterials are attracting great attention [1]. Various new materials have been developed in the last two decades, aiming to block non-ionizing radiation, such as silicon rubbers, composites based on conductive polymers, and others. Among new materials, graphene and its composites stand out due to their chemical stability and resistance to water, acids, and alkaline conditions, as well as their flexibility, low mass, electrical conductivity, and surface area [2,3]. Graphene consists of sp2 hybridized C atoms, organized in aromatic 6-membered rings. This structure made graphene non-polar and dispersible only in non-polar organic solvents. However, graphene is hydrophobic and cannot be dispersed in water. To achieve the functionalization of cotton fibers without additional agents, graphene oxide—a hydrophilic derivative—was chosen for functionalization. By dipping cotton fabrics into an aqueous dispersion of graphene oxide, the fabric was functionalized, followed by the chemical reduction of the graphene oxide. Cotton fabric was immersed in a vitamin C water solution and heated at 85°C for 5 minutes to achieve chemical reduction. This ensured the stability of the graphene-to-fabric bond. These materials were also functionalized with rare-earth nanoparticles based on samarium and gadolinium using the same procedures. The resulting fabrics showed over 75% efficiency in blocking non-ionizing radiation, but also varying degrees of biocompatibility toward surface-level, healthy skin cells (keratinocytes, HaCaT cell line). References [1] D. Marinković, S. Dorontić, et al., Nanomaterials 15, 541, 2025. [2] M. Milenković et al., International Journal of Molecular Sciences, 25(24), 13401, 2024. [3] Prekodravac Filipovic, et al., Chemical Engineering Journal Advances, 24, 100873, 2025. Acknowledgement This research was supported by the European Union’s Horizon Europe Coordination and Support Actions Programme under grant agreement No 101079151-GrInShield. The authors thank the Ministry of Science, Technological Development and Innovation of the Republic of Serbia (grant number 451-03-136/2026-03/ 200017).

Keywords: graphene, graphene oxide, cotton, EMI shielding