Elastic and Degradable Cyclodextrin Nanofibrous Aerogel: Enhanced Dynamic Thermal Management and Broadband Sound Absorption

The sustainable development of human society is driving an increasing demand for environmentally friendly materials that exhibit both acoustic absorption and efficient heat transfer control. To date, a limited number of aerogels with adjustable thermal properties have been reported, and these are primarily composed of synthetic polymers or fibers. In this study, bio-based crosslinked polyacrylonitrile/ β -oligomers (PAN/P- β -CD) nanofibrous aerogel (CPNA) were prepared through directional freeze-drying and thermal treatment. The resulting aerogels demonstrate excellent elasticity, including remarkable compressive cycle durability, retaining 87.5% strength after 100 cycles, and stable elasticity over a wide temperature range (-20 ∼ 180 °C). These exceptional mechanical properties confer thermal management capabilities to CPNA aerogels. The CPNA aerogels exhibit dynamic thermal conductivity under varying compressive strain, with thermal conductivity values as low as 22.9 mW/mK. Due to their well-designed hierarchical porous structure and unique nano-sized cavities of cyclodextrin, CPNA aerogels display broadband sound absorption performance, achieving a noise reduction coefficient (NRC) value of 0.67. Furthermore, the bio-based CPNA aerogels degraded in alkaline solutions. This work expands the applications of bio-aerogels in some environments that require materials with excellent sound absorption and adjustable thermal management properties.