Seasonal Thermal Management and Fire-Resistant Aramid Nanofiber/MXene-NH2 Aerogel for Enhanced Safety and Year-Round Energy Saving

Although aerogel thermal management materials for daily routine environments are widely investigated, the development of functionally integrated aerogels for sustainable thermal regulation in diverse hot and cold environments remains a formidable challenge. Meanwhile, the inherent brittleness of porous skeletons limits their normal operation. Here, we demonstrate an asymmetric structure of aramid nanofiber (ANF)/MXene-NH2 aerogel (ASAMA) for sustainable thermal regulation while maintaining high tensile strength. By integrating different thermal conductivities brought by the asymmetric structure, solar-thermal energy conversion ability derived from MXene-NH2, high solar reflectivity, and mid-infrared emissivity of ANF, ASAMA successfully achieves sustainable thermal regulation in both hot and cold environments. In simulate environments, ASAMA can keep a suitable temperature of 20 degrees C in a frigid environment of -5 degrees C via the synergistic effect of solar-thermal conversion and thermal conductivity. Moreover, it provides efficient thermal buffering through its high solar reflectivity, mid-infrared emissivity, and thermal insulation, which reduce the environment temperature to 28 degrees C from the high temperature of 40 degrees C. The resulting ASAMA exhibits high tensile strength (2.98 MPa), superinsulation from -10 to 280 degrees C, and durable combustion protection for 6 min. The design of these asymmetrically structured aerogels holds promise for widespread application in low-energy thermal regulation amid changing climates.