Bioinspired large-scale aligned porous materials assembled with dual temperature gradients.
Bioinspired large-scale aligned porous materials assembled with dual temperature gradients.
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DOI：
10.1126/sciadv.1500849
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发表时间：
2015-12
期刊：
影响因子：
13.6
通讯作者：
Ritchie RO
中科院分区：
文献类型：
--
作者：
Bai H;Chen Y;Delattre B;Tomsia AP;Ritchie RO
一种双向冷冻方法，将陶瓷颗粒组装成厘米级排列的多孔珍珠质状支架。天然材料，如骨头、牙齿、贝壳和木材，尽管是多孔的，而且是由脆弱的成分组成的，但仍表现出出色的性能。通常，它们代表了设计坚固，坚韧和轻质材料的灵感来源。虽然已经引入了许多技术来创建这样的结构，但孔隙率的长程有序以及最终结构的精确控制仍然难以实现。这些限制严重阻碍了旨在更大应用的分层结构的按比例放大制造。我们报告了一种双向冷冻技术，成功地组装成支架陶瓷颗粒与大规模对齐，层状，多孔，珍珠质样结构和长程有序的厘米级。这是通过用聚二甲基硅氧烷（PDMS）楔形物修饰冷指来实现的，以控制双温度梯度下冰晶的成核和生长。我们的方法可以提供一种制造新型生物启发结构材料的有效方法，特别是复合材料等先进材料，其中需要对结构进行更高水平的控制。
A bidirectional freezing method to assemble ceramic particles into porous nacre-like scaffolds aligned over centimeter-scales. Natural materials, such as bone, teeth, shells, and wood, exhibit outstanding properties despite being porous and made of weak constituents. Frequently, they represent a source of inspiration to design strong, tough, and lightweight materials. Although many techniques have been introduced to create such structures, a long-range order of the porosity as well as a precise control of the final architecture remain difficult to achieve. These limitations severely hinder the scale-up fabrication of layered structures aimed for larger applications. We report on a bidirectional freezing technique to successfully assemble ceramic particles into scaffolds with large-scale aligned, lamellar, porous, nacre-like structure and long-range order at the centimeter scale. This is achieved by modifying the cold finger with a polydimethylsiloxane (PDMS) wedge to control the nucleation and growth of ice crystals under dual temperature gradients. Our approach could provide an effective way of manufacturing novel bioinspired structural materials, in particular advanced materials such as composites, where a higher level of control over the structure is required.