A double cross-linked biomass aerogel with flame retardancy, thermal insulation and antibacterial properties

Biomass aerogels are emerging as green and sustainable materials. Researchers have shown growing interest in their development and practical applications. Among them, cellulose aerogels have demonstrated strong potential in thermal insulation, tissue engineering, and building components. In this study, we used gelatin (G), cellulose nanofibers (CNF), and phytic acid (PA) as raw materials. We fabricated a biomass aerogel with an anisotropic structure through directional freezing and freeze-drying. The resulting aerogel forms a double cross-linked network. Hydrogen bonding and electrostatic interactions stabilize this network. The aerogel exhibits excellent mechanical performance. It also provides effective thermal insulation. In addition, it shows good flame retardancy and antibacterial activity. The aerogel developed in this research is composed of biomass materials with low cost, abundant sources, and a simple preparation process, providing a solid foundation for replacing traditional thermal insulation materials and addressing the current energy crisis.