Extreme mechanical resilience of self-assembled nanolabyrinthine materials
Extreme mechanical resilience of self-assembled nanolabyrinthine materials
复制标题
DOI：
10.1073/pnas.1916817117
复制
发表时间：
2020-03-17
影响因子：
11.1
通讯作者：
Kochmann, Dennis M.
中科院分区：
文献类型：
--
作者：
Portela, Carlos M.;Vidyasagar, A.;Kochmann, Dennis M.
几十年来，具有可裁剪特性的低密度材料一直吸引着人们的注意，但在大规模制造的同时能够弹性容忍极端力量和变形的坚硬材料仍然是罕见的发现。受自然启发的设计，如分层复合材料和仿原子晶格结构，已经实现了机械性能的最佳组合，但由于添加剂制造技术的限制，机械可调整性有限，长期稳定性有限，产量低。基于聚合物乳液通过调幅分解的自然自组装，我们展示了一种可扩展制造超低密度非周期壳基陶瓷材料的概念，具有数十纳米量级的特征和立方厘米量级的样品体积。在分离过程模拟的指导下，我们数值地表明，自组装壳体的曲率可以产生接近最优的随密度变化的刚度比例，并且我们通过实验证明，精心选择的拓扑、几何和基础材料的组合可以在设计的产品中产生优异的机械弹性。我们的方法提供了一条利用自组装方法设计和可扩展制造超周期和非梁基纳米结构材料的途径，该材料同时具有定向可调谐、高刚性和不可超越的可恢复性和边缘劣化。
Low-density materials with tailorable properties have attracted attention for decades, yet stiff materials that can resiliently tolerate extreme forces and deformation while being manufactured at large scales have remained a rare find. Designs inspired by nature, such as hierarchical composites and atomic lattice-mimicking architectures, have achieved optimal combinations of mechanical properties but suffer from limited mechanical tunability, limited long-term stability, and low-throughput volumes that stem from limitations in additive manufacturing techniques. Based on natural self-assembly of polymeric emulsions via spinodal decomposition, here we demonstrate a concept for the scalable fabrication of nonperiodic, shell-based ceramic materials with ultralow densities, possessing features on the order of tens of nanometers and sample volumes on the order of cubic centimeters. Guided by simulations of separation processes, we numerically show that the curvature of self-assembled shells can produce close to optimal stiffness scaling with density, and we experimentally demonstrate that a carefully chosen combination of topology, geometry, and base material results in superior mechanical resilience in the architected product. Our approach provides a pathway to harnessing self-assembly methods in the design and scalable fabrication of beyond-periodic and nonbeam-based nano-architected materials with simultaneous directional tunability, high stiffness, and unsurpassed recoverability with marginal deterioration.