Enhancement of flame-retardancy and self-extinguishing in cellulose paper by bio-based phytic acid chelate-mediated interfacial assembly of Mg(OH)₂

Cellulose-based paper, widely used in cultural heritage preservation and art, suffers from inherent flammability. Conventional phosphorus-based flame retardants, derived from depleting phosphate ores, necessitate sustainable alternatives. This study introduces an innovative layer-by-layer assembly strategy to fabricate biomass-derived MH-P@Mn and MH-P@Ni core-shell flame retardants. Phytic acid, a biogenic phosphorus source, chelates metal ions (Mn 2+ /Ni 2+ ) to form stable coatings on magnesium hydroxide. When applied to cellulose paper, these materials exhibit superior flame-retardant performance compared to commercial phosphorus-based counterparts, particularly at medium-to-high loadings. Mechanistically, they enhance inert gas emission during pyrolysis, delaying thermal degradation. The mild, rapid synthesis enables development of eco-friendly, multifunctional cellulose paper with enhanced fire resistance and sustainable phosphorus utilization, promising diverse applications.