Quick and efficient flame-retardant, antibacterial and antifungal treatment for high-performance cellulose paper

Cellulose-based paper is widely used in cultural communication, art appreciation, and cultural relic protection, but is susceptible to fire and mildew. Traditional protective materials have negative impacts on the appearance, flexibility, and writability of paper, resulting in severely limited applications. Herein, we demonstrate a quick and effective approach for enhancing the flame retardancy, antibacterial, and antifungal properties of cellulose papers by assembling polyhexamethylene biguanide (PHMB) and sodium polyphosphate (PSP). By exploiting hydrogen bonding and electrostatic interactions, PHMB and PSP can assemble into micro-nano protuberances that are deposited on the surface of the paper through a 30 s dip-treating technology. The PHMB/PSP layers promote the formation of char layer when exposed to flame, providing the paper with self-extinguishing property with a limiting oxygen index value of 34.5 % and an 84.0 % reduction in peak heat release rate. Meanwhile, the treated papers exhibit excellent antibacterial activity against S. aureus (>99.99 %) and appreciable fungal resistance against T. viride (Grade 1). Importantly, the treatment does not alter the appearance, mechanical stability, and writability of the paper. Owing to the mild conditions and fast processability, this study promotes the wide development of advanced high-performance cellulose paper with combined fire-safety, antibacterial, and antifungal properties for diverse applications.