3D Printing of Salt as a Template for Magnesium with Structured Porosity
3D Printing of Salt as a Template for Magnesium with Structured Porosity
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DOI：
10.1002/adma.201903783
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发表时间：
2019-09-01
影响因子：
29.4
通讯作者：
Loeffler, Joerg F.
中科院分区：
文献类型：
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作者：
Kleger, Nicole;Cihova, Martina;Loeffler, Joerg F.
孔隙率是联合收割机重量轻、表面积大和密度可调的广泛应用中的一个基本特征。使用盐浸技术，可以通过多种化学物质轻松制备多孔材料。然而，这种模板方法迄今为止仅限于制造具有随机孔隙率和相对简单的宏观形状的结构。在这里，报告了一种技术，该技术将盐浸出的容易性与增材制造（AM）提供的复杂成形可能性相结合。通过调整表面活性剂和溶剂的组成，基于盐的糊剂被流变工程化，并通过直接油墨写入印刷成网格状结构，显示从亚毫米到宏观尺度的结构化孔。作为概念的证明，干燥和烧结的NaCl模板用镁（Mg）渗透，由于其高度氧化性和高蒸气压，镁（Mg）通常对通过常规AM技术处理具有高度挑战性。除盐后，得到了具有良好控制的有序孔隙率的镁支架。可调的机械性能和可预测的人体生物吸收的潜力使这些镁支架对生物医学植入物具有吸引力，并展示了这种添加剂技术的巨大潜力。
Porosity is an essential feature in a wide range of applications that combine light weight with high surface area and tunable density. Porous materials can be easily prepared with a vast variety of chemistries using the salt-leaching technique. However, this templating approach has so far been limited to the fabrication of structures with random porosity and relatively simple macroscopic shapes. Here, a technique is reported that combines the ease of salt leaching with the complex shaping possibilities given by additive manufacturing (AM). By tuning the composition of surfactant and solvent, the salt-based paste is rheologically engineered and printed via direct ink writing into grid-like structures displaying structured pores that span from the sub-millimeter to the macroscopic scale. As a proof of concept, dried and sintered NaCl templates are infiltrated with magnesium (Mg), which is typically highly challenging to process by conventional AM techniques due to its highly oxidative nature and high vapor pressure. Mg scaffolds with well-controlled, ordered porosity are obtained after salt removal. The tunable mechanical properties and the potential to be predictably bioresorbed by the human body make these Mg scaffolds attractive for biomedical implants and demonstrate the great potential of this additive technique.