Gao Yu-Cheng, Qin Bing, Wen Shao-Meng, You Yang, Xue JingZhe, Yin Yi-Chen, Ma Zhi-Yuan, Dong Kang, Meng Yu-Feng, Manke Ingo, Zhang Si-Chao, Yu Zhi-Long, Yu Shu-Hong
Division of Nanomaterials & Chemistry, Hefei National Research Center for Physical Sciences at the Microscale, Institute of Energy, Hefei Comprehensive National Science Center, Department of Chemistry, Institute of Biomimetic Materials & Chemistry, Anhui Engineering Laboratory of Biomimetic Materials, University of Science and Technology of China, Hefei 230026, P.R. China.
School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, P.R. China.
Nano Lett. 2023 Oct 11;23(19):9011-9019. doi: 10.1021/acs.nanolett.3c02654. Epub 2023 Sep 7.
Freeze-casting has been wildly exploited to construct porous ceramics but usually requires costly and demanding freeze-drying (high vacuum, size limit, and supercooled chamber), which can be avoided by the ambient pressure drying (APD) technique. However, applying APD to freeze-cast ceramic based on an aqueous suspension is still challenging due to inert surface chemistry. Herein, a modified APD strategy is developed to improve the drying process of freeze-cast ceramics by exploiting the simultaneous ice etching, ionic cross-linking, and solvent exchange under mild conditions (-10-0 °C, ambient pressure). This versatile strategy is applicable to various ceramic species, metal ions, and freezing techniques. The incorporated metal ions not only enhance liquid-phase sintering, producing ceramics with higher density and mechanical properties than freeze-cast counterparts, but also render customizable coloration and antibacterial property. The cost-/time-efficient APD is promising for mass production and even successive production of large-size freeze-cast ceramics that exceed the size of commercial freeze-dryers.
冷冻铸造已被广泛用于制造多孔陶瓷，但通常需要昂贵且要求苛刻的冷冻干燥（高真空、尺寸限制和过冷腔室），而环境压力干燥（APD）技术可以避免这些问题。然而，由于陶瓷表面化学性质惰性，将APD应用于基于水悬浮液的冷冻铸造陶瓷仍然具有挑战性。在此，我们开发了一种改进的APD策略，通过在温和条件（-10-0°C，环境压力）下利用同时进行的冰蚀刻、离子交联和溶剂交换来改善冷冻铸造陶瓷的干燥过程。这种通用策略适用于各种陶瓷种类、金属离子和冷冻技术。引入的金属离子不仅增强了液相烧结，从而生产出比冷冻铸造陶瓷具有更高密度和机械性能的陶瓷，还赋予了可定制的颜色和抗菌性能。这种具有成本效益和时间效益的APD对于大规模生产甚至连续生产超过商业冷冻干燥机尺寸的大型冷冻铸造陶瓷具有广阔前景。
