Enhancing fire safety, electromagnetic interference shielding, and photothermal conversion performances of wearable polyamide fabrics through eco-friendly coatings

The demand for smart textiles in wearable technology has significantly increased in the last decade. However, the inherent flammability of most textiles poses a big challenge, especially when exposed to elevated surface temperatures induced by electrical or optical stimuli, increasing the risk of fire. The process of synthesizing flame retardants involves the use of organic solvents, which is not in line with the requirements of sustainable development. This research focuses on establishing an eco-friendly and stable coating for polyamide 6 (PA6) fabric through a solvent-free synthesis and innovative alternating deposition method. It has been demonstrated that the treated PA6 fabric exhibits rapid self-extinguishing properties, eliminating melt dripping and achieving a remarkable limiting oxygen index of 25.5%. Furthermore, the peak heat release rate and total heat release rate of the treated PA6 fabric decrease by 32.9% and 22.7%, respectively, compared to that of the control PA6. Under simulated sunlight exposure at an intensity of 150 mW·cm−2, the treated PA6 fabric rapidly reaches a surface temperature of 78.6 °C within 300 s. Additionally, the treated PA6 fabric demonstrates an electromagnetic interference (EMI) shielding efficiency of 24.0 dB in the X-band, highlighting the efficacy of the innovative coating. This result is attributed to the conductive network formed by the alternating deposition of MXene and polyphosphamide. This work not only improves the fire safety in wearable textiles but also presents a promising and green strategy for developing multifunctional wearable textiles with enhanced safety features.