LAUSR

Excellent thermal insulating materials are highly demanded in various applications including buildings, aerospace and sport equipment. However, in practical applications, the performance of thermal insulating materials usually deteriorates under diverse temperature and humidity conditions. Therefore, it is highly essential to construct a bulk material that exhibits outstanding thermal insulation performance under extremely humid and hot environment. In this work, we have conceived a green and effective strategy to fabricate a superhydrophobic and compressible polyvinylidene fluoride/polyimide (PVDF/PI) nanofiber composite aerogel via electrospinning and freeze-drying technique. Interestingly, the PVDF nanofibers and PI nanofibers function as the hydrophobic fibrous framework and mechanical support skeleton, respectively, forming a robust three-dimensional framework with good mechanical flexibility. The PVDF/PI aerogel possesses outstanding superhydrophobic feature (water contact angle of 152°) and low thermal conductivity (31.0 mW m −1 K −1 ) at room temperature. Significantly, even at 100% relative humidity (80°C), the PVDF/PI aerogel still exhibits a low thermal conductivity of only 48.6 mW m −1 K −1 , which outperforms the majority of commercial thermal insulating materials. Therefore, the novel PVDF/PI aerogel is promising as an excellent thermal insulating material for the applications in high temperature and humid environment. 优异的隔热材料在建筑、航空航天和体育设备等领域有着 广泛的应用需求. 然而, 在实际应用中, 隔热材料在不同温度和湿度 条件下, 其性能往往会恶化. 因此, 构建在极端湿热环境下仍具有出 色的隔热性能的块状材料是非常重要的. 在本工作中, 我们构思了 一种绿色制备策略, 即通过静电纺丝和冷冻干燥技术来制备超疏 水且可压缩的聚偏氟乙烯/聚酰亚胺(PVDF/PI)纳米纤维复合气凝 胶. PVDF纳米纤维和PI纳米纤维分别充当疏水性纤维骨架和机械 支撑骨架, 形成具有良好机械柔韧性的坚固的三维框架. PVDF/PI 气凝胶在室温下具有出色的超疏水特性(水接触角为152°)和低导 热性(31.0 mW m −1 K −1 ). 同时, 在100%湿度(80°C)下, PVDF/PI气凝 胶仅显示出48.6 mW m −1 K −1 的低热导率, 其性能优于大多数商业 绝热材料. 因此, 新型的PVDF/PI复合气凝胶有望成为高温和高湿 环境中应用的优良隔热材料.