Flame-Retardant and Fire-Sensing Packaging Papers Enabled by Diffusion-Driven Self-Assembly of Graphene Oxide and Branched Polyethyleneimine Coatings

Paper has gained popularity as a packaging material due to its reduced environmental impact compared with non-degradable alternatives. However, flammability poses safety risks, prompting research on enhancing flame retardancy. This work introduces diffusion-driven self-assembly strategy (DDSAS) create functional graphene oxide (GO) coating various papers. DDSAS involves infiltrating the paper’s cellulose microfiber network branched polyethyleneimine (b-PEI), which binds firmly microfibers. Electrostatic interactions between GO and b-PEI then drive assembly into densely stacked, layered structure paper surface. provides physical barrier against flames generates incombustible gases (CO2, H2O, NO2, NO) when heated, diluting surrounding oxygen concentration acting heat insulation layer. These factors increase retardancy of treated papers ten-fold. Additionally, gradual reduction upon heating forms (rGO) paper, significantly increasing electrical conductivity. As result, flame-retardant not only prevent fire from spreading but can also act sensors by triggering an alarm signal at early stages contact fire. In summary, this offers rational for designing manufacturing materials.