Anisotropic Biomass Aerogels with Enhanced Mechanical, Flame Retardancy, Smoke Suppression, and Antibacterial Performances for Thermal Insulation

Biomass aerogels are expected to become thermal insulation materials to overcome the world environment and energy crisis due to their excellent ecological friendliness and thermal insulation performances. In this paper, thermal insulation biomass aerogels were designed based on ionic and physical double cross-linking strategies and directed freezing methods using pectin (P), gelatin (G), and phytic acid (PA) as raw materials. They exhibited remarkable anisotropic structural characteristics, achieving excellent mechanical and thermal insulation performances (thermal conductivities reached 18.95 and 13.40 mW/mK) in different directions. Due to the presence of gelatin and phytic acid, aerogels showed excellent flame retardancy, smoke suppression, and antibacterial performances (antibacterial rates against Staphylococcus aureus and Escherichia coli reached 41.33 and 82.29%, respectively). Furthermore, the coating-modified aerogels showed amazing surface waterproof performance (hydrophobic angle increased to 110°). This study provided a new idea for the preparation of thermal insulation materials with excellent mechanical, flame retardancy, smoke suppression, antibacterial, and surface waterproof performances.