Wang Lukai, Feng Junzong, Luo Yi, Jiang Yonggang, Zhang Guojie, Feng Jian
Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, Hunan, 410073, P. R. China.
Small Methods. 2022 May;6(5):e2200045. doi: 10.1002/smtd.202200045. Epub 2022 Mar 28.
Ceramic aerogels have great potential in the areas of thermal insulation, catalysis, filtration, environmental remediation, energy storage, etc. However, the conventional shaping and post-processing of ceramic aerogels are plagued by their brittleness due to the inefficient neck connection of oxide ceramic nanoparticles. Here a versatile thermal-solidifying direct-ink-writing has been proposed for fabricating heat-resistant ceramic aerogels. The versatility lies in the good compatibility and designability of ceramic inks, which makes it possible to print silica aerogels, alumina-silica aerogels, and titania-silica aerogels. 3D-printed ceramic aerogels show excellent high-temperature stability up to 1000 °C in air (linear shrinkage less than 5%) when compared to conventional silica aerogels. This improved heat resistance is attributed to the existence of a refractory fumed silica phase, which restrains the microstructure destruction of ceramic aerogels in high-temperature environments. Benefiting from low density (0.21 g cm ), high surface area (284 m g ), and well-distributed mesopores, 3D-printed ceramic aerogels possess a low thermal conductivity (30.87 mW m K ) and are considered as ideal thermal insulators. The combination of ceramic aerogels with 3D printing technology would open up new opportunities to tailor the geometry of porous materials for specific applications.
陶瓷气凝胶在隔热、催化、过滤、环境修复、能量存储等领域具有巨大潜力。然而，由于氧化物陶瓷纳米颗粒的颈部连接效率低下，陶瓷气凝胶的传统成型和后处理受到其脆性的困扰。在此，提出了一种通用的热固化直接墨水书写方法来制备耐热陶瓷气凝胶。其通用性在于陶瓷墨水具有良好的兼容性和可设计性，这使得打印二氧化硅气凝胶、氧化铝 - 二氧化硅气凝胶和二氧化钛 - 二氧化硅气凝胶成为可能。与传统二氧化硅气凝胶相比，3D打印的陶瓷气凝胶在空气中高达1000°C时表现出优异的高温稳定性（线性收缩小于5%）。这种提高的耐热性归因于存在难熔气相二氧化硅相，它抑制了陶瓷气凝胶在高温环境中的微观结构破坏。受益于低密度（0.21 g/cm³）、高比表面积（284 m²/g）和分布均匀的中孔，3D打印的陶瓷气凝胶具有低导热率（30.87 mW/(m·K)），被认为是理想的隔热材料。陶瓷气凝胶与3D打印技术的结合将为针对特定应用定制多孔材料的几何形状开辟新的机会。
