Phase Change Microcapsule-Functionalized Silk Nanofibrous Aerogel for Thermal Management

Silk fiber is an attractive natural material for thermal management applications due to its abundance, excellent mechanical properties, low thermal conductivity, and low-temperature tolerance. In this study, nanofibrous aerogels were prepared by utilizing natural silk nanofibrils (SNFs) as building blocks and further functionalized with phase change microcapsules (PCMs). The potential of the resulting PCM-functionalized SNF aerogel (PS aerogel) as a thermal management material was demonstrated. The SNF aerogel can be produced on a large scale and demonstrated excellent thermal insulation performance with a low thermal conductivity of 28.74 mW/(m·K). The PCMs could be uniformly and stably anchored onto the SNF surfaces after being incorporated into the SNF aerogels. The PS aerogel with 100% PCM loading showed a phase change enthalpy of 60.69 J/g and simultaneously maintained a low thermal conductivity of 29.92 mW/(m·K). Furthermore, house-model experiments showed that the PS aerogels not only retained exceptional thermal insulation but also demonstrated active heat absorption/release capabilities for temperature regulation with a buffering capacity of approximately 3 °C. The scalability, ultralightweight, and thermal regulation capabilities of PS aerogels position them as promising candidates for thermal management materials.