Atomistic insights into thermal degradation and multifunctional design of layer-by-layer assembled PA/PEI/AgNWs cotton fabrics

Modern environments impose complex safety requirements on textiles. Therefore, developing multifunctional textiles with integrated flame retardancy, electromagnetic interference (EMI) shielding, and antibacterial properties is of great significance. In this study, a robust ternary P/N/Ag nanocoating was constructed on cotton fabrics via layer-by-layer (LbL) assembly of phytic acid (PA) and polyethyleneimine (PEI), followed by the impregnation of a silver nanowire (AgNW) conductive network. This hierarchical architecture endowed the cotton fabric with exceptional multifunctionality. The optimized composite fabric exhibited superior fire safety, achieving a limiting oxygen index (LOI) of up to 49.8% and a 91.7% reduction in peak heat release rate (PHRR). Mechanistic investigation revealed that the AgNWs act as reinforcing skeletons within the intumescent char layer, significantly enhancing the condensed-phase barrier effect against heat and oxygen. Furthermore, the construction of a highly conductive network resulted in a low sheet resistance of 2.09 Ω·mm and an EMI shielding effectiveness (SE) of 32.65 dB in the X-band. Additionally, the functionalized fabric demonstrated excellent ultraviolet (UV) resistance (Ultraviolet Protection Factor (UPF) > 130) and strong antibacterial activity, with a 99.9% reduction rate against both E. coli and S. aureus . This work provides a facile and effective strategy for fabricating high-performance multifunctional textiles with promising applications in personal protection and smart electronics.