Superior flame retardancy, thermal insulation, and mechanical properties of konjac glucomannan/sodium alginate biomass aerogel modified by supramolecular assembled phytic acid-melamine nanosheet.

The development of biomass-based eco-friendly aerogel with superior flame retardancy, thermal insulation, and mechanical properties at the same time has long been a tough challenge. In this study, the polysaccharide-based aerogels composed of konjac glucomannan, sodium alginate, and supramolecular assembled melamine phytate (MPA) nanosheets were successfully fabricated through the freeze-drying method. Owing to the excellent charcoal-forming and non-combustible gas-releasing effect of MPA nanosheets, the thermal stability and flame retardancy properties of the aerogels were both significantly enhanced, with the highest limiting oxygen index value reaching 42.4 %. Meanwhile, appropriate MPA embedded in the pore walls greatly enhanced the compressive strength of the aerogel (364.9 kPa) and can withstand >7100 times its weight without visual deformation. Moreover, the thermal insulation effect was quite attractive with a thermal conductivity of 0.0385-0.0420 W/mK. The present work provided an environmentally friendly method for the fabrication of multifunctional sustainable fire-resistant aerogels, which showed promising prospects in the future.