Department of Materials Science and Engineering and the Russel Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, 32000 Haifa, Israel.
The European Synchrotron, CS 40220, 38043 Grenoble Cedex 9, France.
Science. 2017 Dec 8;358(6368):1294-1298. doi: 10.1126/science.aaj2156.
In contrast to synthetic materials, materials produced by organisms are formed in ambient conditions and with a limited selection of elements. Nevertheless, living organisms reveal elegant strategies for achieving specific functions, ranging from skeletal support to mastication, from sensors and defensive tools to optical function. Using state-of-the-art characterization techniques, we present a biostrategy for strengthening and toughening the otherwise brittle calcite optical lenses found in the brittlestar This intriguing process uses coherent nanoprecipitates to induce compressive stresses on the host matrix, functionally resembling the Guinier-Preston zones known in classical metallurgy. We believe that these calcitic nanoparticles, being rich in magnesium, segregate during or just after transformation from amorphous to crystalline phase, similarly to segregation behavior from a supersaturated quenched alloy.
与合成材料不同，生物体产生的材料是在环境条件下形成的，并且只能选择有限的元素。然而，生物体展现出了实现特定功能的优雅策略，从骨骼支撑到咀嚼，从传感器和防御工具到光学功能。使用最先进的表征技术，我们提出了一种用于增强和增韧脆性星骨中易碎方解石光学透镜的生物策略。这个有趣的过程利用相干纳米沉淀物在主基质上产生压应力，其功能类似于经典冶金学中已知的古伊涅尔-普雷斯顿区。我们相信，这些富含镁的方解石纳米颗粒在从非晶态向晶态转变的过程中或转变之后会发生偏析，类似于过饱和淬火合金的偏析行为。
