Flame-retardant and thermal insulating biomass aerogel with super-elasticity

Biomass aerogels possessing both resilience and flame retardance exhibit great potential as alternatives to fossilbased thermal insulators. Nevertheless, the functional applications of elastic biomass aerogels are impeded by their poor resilience persistence, especially at low temperatures. Herein, a synergetic strategy was proposed for designing biomass aerogels with exceptional elasticity across a broad temperature range (from 150 degrees C to -78 degrees C), by strategically manipulating their microstructure and implementing a chemically cross-linked network. The resultant aerogels suffered from slight plastic deformation of only 6.1 % even after 1000 loading-unloading cycles at a strain of 60 %, manifesting super-elastic performance. Additionally, the structure and resilience of aerogel can be well maintained even under frigid temperatures (-78 degrees C). Because firmly crosslinked networks and loosely packed microstructures with elongated cell walls were constructed to minimize plastic deformation and bending stress, thereby suppressing structural destruction. Furthermore, the resulting biomass aerogel exhibited a remarkable combination of advantageous properties including lightweight, flame retardance (limiting oxygen index of 29 %), thermal insulation (32.8 mW m- 1 K-1) and infrared stealth. This research offers new insights into the design of elastic biomass aerogels with exceptional overall performance.