Abstract:

Objective This study aimed to develop a multifunctional polyester fabric with high conductivity， superior electromagnetic shielding efficiency， and excellent ultraviolet （UV） protection through a simple and efficient process， in order to address the limitations of conventional multi-step or multi-agent finishing methods. By exploring methods for reducing a single functional agent， graphene oxide （GO）， this research seeks to provide a practical solution for integrated functional finishing of textiles.

Method Pure GO paste at concentrations of 30， 50， and 70 g/L was coated onto a polyester fabric at varying thicknesses （0.01， 0.04， 0.07， 0.10 mm）. The coated GO was then chemically reduced on the fabric using two different reducing agents， i.e. sodium hydrosulfite and hydroiodic acid. The performance of the finished fabrics， designated as RGO coated polyester， was systematically evaluated. Characterization involved measuring surface resistance， electromagnetic shielding efficiency， and UV protection factor （UPF）. The surface morphology and degree of reduction were analyzed using scanning electron microscopy （SEM） and Raman spectroscopy， respectively. Durability was assessed through washing fastness tests.

Results The functional properties of the RGO coated polyester fabrics significantly improved with increasing GO concentration and coating thickness. The choice of reducing agent was found to have a profound impact. Fabrics reduced with hydroiodic acid exhibited far superior performance compared to those reduced with sodium hydrosulfite. Under the optimal condition of 70 g/L GO and a 0.04 mm coating， hydroiodic acid-reduced fabric achieved a very low surface resistance of 0.18 kΩ/cm and an outstanding electromagnetic shielding efficiency exceeding 80% across the 30 MHz to 3 GHz frequency range. Its UV protection was exceptional， with the UPF value soaring from 9.31 （untreated fabric） to 1981.18， effectively blocking nearly all UV radiation. In stark contrast， fabric reduced with sodium hydrosulfite under the same coating condition showed much higher resistance （2.38 kΩ/cm）， lower electromagnetic shielding efficiency （<20%）， and UPF （1 172.85）. SEM images confirmed that hydroiodic acid reduction resulted in a more continuous， uniform， and complete RGO coating layer covering the fiber surfaces and filling inter-fiber gaps， explaining the enhanced conductivity and shielding. Raman spectra verified the successful reduction of GO to RGO by both agents， with hydroiodic acid showing a stronger signal. Durability tests indicated good fastness of the coating. After 50 washes， the hydroiodic acid-reduced fabric retained a high electromagnetic shielding efficiency of about 70% and a UPF above 1800， though with a slight increase in surface resistance. A trade-off of the coated fabric was a modest （<5%） loss in fabric tensile strength due to the acidic action of hydroiodic acid.

Conclusion This research demonstrates that a simple GO coating followed by hydroiodic acid reduction is a highly effective single-process method for endowing polyester fabric with integrated high-performance conductivity， electromagnetic shielding efficiency， and UV protection. The use of hydroiodic acid as a reducing agent is identified as a critical factor， as it facilitates a more complete reduction of GO to RGO， forming a superior conductive network on the fabric compared to the conventional sodium hydrosulfite process. The finished fabrics exhibit remarkable and durable surface resistance， electromagnetic shielding efficiency， and UV protection. This work provides a valuable and practical strategy for developing advanced functional textiles. Future research could focus on optimizing the hydroiodic acid reduction parameters to further minimize fabric strength loss or exploring environmentally friendly alt

Key words: graphene oxide, reduced graphene oxide, polyester, functional finish, electromagnetic shielding, ultraviolet protection, electrical conductivity