Fiber Sedimentation and Layer-By-Layer Assembly Strategy for Designing Biomimetic Quasi-Ordered Mullite Fiber Aerogels as Extreme Conditions Thermal Insulators.
Fiber Sedimentation and Layer-By-Layer Assembly Strategy for Designing Biomimetic Quasi-Ordered Mullite Fiber Aerogels as Extreme Conditions Thermal Insulators.
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DOI：
10.1021/acsami.3c09418
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发表时间：
2023-09
影响因子：
9.5
通讯作者：
Wenjie Li;Yuncong Jiang;Han Liu;Chen Wang;Xin Zhou;Siyi Jiang;Yuwen Mu;Linyan Wang;
中科院分区：
文献类型：
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作者：
Wenjie Li;Yuncong Jiang;Han Liu;Chen Wang;Xin Zhou;Siyi Jiang;Yuwen Mu;Linyan Wang;
陶瓷纤维气凝胶是很有吸引力的隔热材料。然而，在热力耦合环境中，它们通常表现出有限的机械强度和相当大的热量传递，这可能导致热失控。受鸟巢和珍珠层的启发，我们提出了一种纤维沉积和层层组装相结合的方法来制备具有准有序结构的超强莫来石纤维气凝胶。纤维层和纤维桥是在纤维沉积自组装过程中构建的。纤维沉淀法通过调节纤维取向来优化MFA的结构。由于具有准有序结构，所制备的MFA具有较高的抗压疲劳性、-196C到1300C的恒温压缩回弹和较低的导热系数(0.034 W·m-1·K-1)。通过有意地将多层MFA压成薄纸，我们大幅提高了MFA的承载能力，并在模拟高温(685°C)和高压(0.9兆帕)的环境下使用一层薄的MFA(3-5 mm)，实现了冷表面和热表面之间的大温差(563°C)。耐压性、机械灵活性和优异的隔热性能相结合，为极端环境下的高效隔热提供了极具吸引力的材料。
Ceramic fiber aerogels are attractive thermal insulating materials. In a thermomechanical coupling environment, however, they often show limited mechanical strength and considerably increased heat transfer which can lead to thermal runaway. In this paper, inspired by bird's nest and nacre, we demonstrate a sample strategy combining fiber sedimentation and layer-by-layer assembly to fabricate ultrastrong mullite fiber aerogels (MFAs) with quasi-ordered structures. The fibrous layers and fiber bridges are constructed in a fiber sedimentation self-assembly process. The fiber sedimentation technique optimizes the structure of the MFAs by regulating the fiber orientation. Owing to the quasi-ordered structure, the fabricated MFAs exhibit the integrated properties of high compression fatigue resistance, temperature-invariant compression resilience from -196 to 1300 °C, and low thermal conductivity (0.034 W·m-1·K-1). By deliberately pressing multilayer MFAs into a thin paper, we substantially enhance the load-bearing capacity of the MFAs and achieve large temperature differences (563 °C) between the cold and hot surfaces by using a thin layer of MFAs (3-5 mm) under the simulated high-temperature (685 °C) and high-pressure (0.9 MPa) environment test. The combination of compression resistance, mechanical flexibility, and excellent thermal insulation provides an appealing material for efficient thermal insulation in extreme environments.