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.

Intermittent Exothermic and Self-Healing Hydrated Salt Gels for Advanced Thermal Management of Underfloor Radiant Heating System.

Phase change materials (PCMs) have great prospects in thermal management applications because they can store and release latent heat. However, they are not suitable for on-demand heating as they can only release heat once. Herein, this work reports the intermittent exothermic of PCMs based on a supersaturated salt solution, exhibiting fully controlled long-term storage of energy, releasing and suspending heat on demand. Due to the high energy barrier, it is difficult for the supersaturated salt solution to nucleate; thus, it can store energy for a long time. Contact with seeds or other foreign objects can destroy the metastable state of the supersaturated salt solution and promote the formation of crystal nuclei, enabling crystallization and heat release on demand. The release of crystallization heat can be interrupted using scissors dip in water. Additionally, self-healing behavior allows it to be recycled and last longer, due to the presence of Fe3+ , inducing strong dynamic reversible non-covalent crosslinking through metal coordination bonds. Furthermore, the hydrated salts gels are applied for thermal management of underfloor radiant heating system, demonstrating four types of intermittent exotherms sequences amazingly. Further, the intermittent exothermic hydrated salts gels provide a more user-friendly thermal management of underfloor radiant heating systems.