Direct observation of mineral-organic composite formation reveals occlusion mechanism.
Direct observation of mineral-organic composite formation reveals occlusion mechanism.
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DOI：
10.1038/ncomms10187
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发表时间：
2016-01-06
影响因子：
16.6
通讯作者：
De Yoreo JJ
中科院分区：
文献类型：
--
作者：
Rae Cho K;Kim YY;Yang P;Cai W;Pan H;Kulak AN;Lau JL;Kulshreshtha P;Armes SP;Meldrum FC;De Yoreo JJ
用有机大分子操纵无机材料使有机体能够创造出骨骼和贝壳等生物矿物质，在这些矿物中，生物大分子被单个晶体中的生物大分子遮挡，可以产生优异的机械性能。目前对这一过程的理解主要来自于对微米级颗粒在冷却熔体中的捕获的研究。在这里，通过用原子力显微镜和微观力学模拟研究方解石中的胶束掺入，我们发现不同的机制支配着纳米尺度的遮挡。通过同时可视化胶束和传播阶跃边缘，我们证明了胶束在咬合过程中经历了显著的压缩，这伴随着空洞的形成。这会产生局部晶格应变，从而提高力学性能。这些结果对天然晶体和合成晶体中包裹体的形成有了新的认识，并将有助于多功能纳米复合晶体的合成。生物大分子的封闭可以赋予生物矿物更高的力学性能。在这里，作者使用原位原子力显微镜和微观力学模拟来跟踪方解石中的胶束掺入，以揭示咬合和空洞形成的机制。
Manipulation of inorganic materials with organic macromolecules enables organisms to create biominerals such as bones and seashells, where occlusion of biomacromolecules within individual crystals generates superior mechanical properties. Current understanding of this process largely comes from studying the entrapment of micron-size particles in cooling melts. Here, by investigating micelle incorporation in calcite with atomic force microscopy and micromechanical simulations, we show that different mechanisms govern nanoscale occlusion. By simultaneously visualizing the micelles and propagating step edges, we demonstrate that the micelles experience significant compression during occlusion, which is accompanied by cavity formation. This generates local lattice strain, leading to enhanced mechanical properties. These results give new insight into the formation of occlusions in natural and synthetic crystals, and will facilitate the synthesis of multifunctional nanocomposite crystals. The occlusion of biomacromolecules can endow biominerals with enhanced mechanical properties. Here, the authors use in situ atomic force microscopy and micromechanical simulations to trace micelle incorporation in calcite to shed light on the mechanism of occlusion and cavity formation.