Conceptual Frameworks and Practice on Nano-Micro Pore Structure Design of Bio-Aerogels

Bio-aerogels have garnered significant attention due to their environmental friendliness and potential for exceptional performance. The pore structure of bio-aerogels includes both pore size and distribution, which significantly determine their functional behaviors, such as filtration, thermal insulation, and sound absorption. This review proposes several conceptual frameworks regarding the design of the pore structure of bio-aerogels, some of which are validated through practical cases. The ice crystal pore-making conceptual framework approach involves controlling the growth of ice crystals to achieve a pre-designed pore structure. The space occupying pore-making conceptual framework is the proactive addition of nano materials to occupy space prior to the formation of ice crystals, facilitating the design of the aerogel's nanoscale pore structure. The conceptual framework of blocks building involves assembling multiple aerogels to create a composite aerogel with a multi-level pore structure. These theoretical considerations contribute to the development of aerogel structural design theory to obtain aerogels with different micro-nano structures.