Preparation and Performance Study of Phytic Acid Cytosine Oxidized Graphene Hybrid Modified Multifunctional Fabric

To address the high flammability of polyethylene terephthalate (PET) fabrics and impart multifunctionality, a phosphorus–nitrogen flame retardant was designed through molecular hybridization of phytic acid and cytosine. This biomolecular-derived strategy was employed to enhance both char formation and gas-phase inhibitory activity. A multifunctional coating was constructed on PET fabric using a stepwise droplet coating and solvent evaporation technique, sequentially applying the synthesized flame retardant, graphene oxide, and polydimethylsiloxane. The modified fabric exhibited remarkable flame retardancy improvements, exhibiting 54.1% and 11.3% reductions in peak heat release rate and total heat release, respectively. Moreover, the treated fabric displayed excellent hydrophobicity with water contact angle of 144.5°, as well as fast fire response (8   s alarm trigger) and sustained signal transmission (1328   s) due to rapid electrical resistance changes upon flame exposure. This study provides a feasible strategy for designing and preparing PET fabrics with flame retardancy, hydrophobicity, and fire alarm functionality.