Sustainable lignocellulose aerogel for air purifier with thermal insulation, flame retardancy, mechanical strength, and its life cycle assessment.

High-performance biomass materials with good thermal insulation, flame retardrancy, and mechanical properties are urgently required for thermal management. Herein, a novel lignocellulose aerogel treated using a recyclable deep eutectic solvent (DES) was physically mixed with tourmaline particles (TPs) to enhance its structural stability, flame retardancy, and mechanical properties. The optimized TPs-modified lignocellulose aerogel (TLA-4) had good comprehensive performances due to the synergistic effect of ammonium sulfate and TPs. Compared with TPs-free lignocellulose aerogel (LA), the total heat release (THR) and heat release rate (HRR) of TLA-4 were reduced by 62.0 % and 66.3 %, respectively, and the limiting oxygen index (LOI) of TLA-4 was drastically enhanced by 74.1 %. TLA-4 also exhibited a low thermal conductivity of 29.67 mW/mK, showing favorable thermal insulation performance. When compressed to 5 %, the mechanical strength of TLA-4 increased by 8.3 times. Meanwhile, the presence of TPs and abundant pores in the aerogel contributed to the release of negative oxygen ions (NOIs), aiding air purification. A life cycle assessment (LCA) indicated that this composite had a minimal environmental impact (EI) in 17 categories compared to other similar aerogels. The proposed strategy for preparing an environment-friendly lignocellulose aerogel offers significant potential for applications in home decoration and building materials.