Material properties of brachiopod shell ultrastructure by nanoindentation
Material properties of brachiopod shell ultrastructure by nanoindentation
复制标题
纳米压痕研究腕足动物壳超微结构的材料特性
DOI：
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发表时间：
2007
影响因子：
3.9
通讯作者：
J. Hughes
中科院分区：
文献类型：
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作者：
A. Pérez;M. Cusack;Wenzhong Zhu;Jennifer England;J. Hughes
产矿生物对生物矿物生产的各个方面都有精密的控制。在含壳生物中，开发了各种各样的矿物织物，反映了需要不同材料特性的不同生活方式。我们对生物矿物结构与材料性质的关系的了解仍然有限，因为它需要在详细的尺度上确定这些性质。纳米压痕，主要应用于工程和材料科学，在这里被用来评估，在微观结构水平上，材料性能的两个方解石腕足动物生活在同一环境中，但不同的生活方式和外壳超微结构。硬度（H）和杨氏弹性模量（E）的值通过纳米压痕来确定。在腕足类贝壳中，方解石半珍珠层提供了比方解石纤维（H=0-3 GPa; E=20-60/80 GPa）更坚硬和更坚硬的结构（H= 3-6 GPa; E =60-110/120 GPa）。 因此，腕足类与方解石半珍珠层可以水泥基板，并保持不动，在其成年生命周期。由于超微结构的存在，生命模式和物质性质之间的这种相关性开始解释为什么生物体使用相同的化学成分（如碳酸钙）产生各种各样的结构。
Mineral-producing organisms exert exquisite control on all aspects of biomineral production. Among shell-bearing organisms, a wide range of mineral fabrics are developed reflecting diverse modes of life that require different material properties. Our knowledge of how biomineral structures relate to material properties is still limited because it requires the determination of these properties on a detailed scale. Nanoindentation, mostly applied in engineering and materials science, is used here to assess, at the microstructural level, material properties of two calcite brachiopods living in the same environment but with different modes of life and shell ultrastructure. Values of hardness (H) and the Young modulus of elasticity (E) are determined by nanoindentation. In brachiopod shells, calcite semi-nacre provides a harder and stiffer structure (H∼3–6 GPa; E=60–110/120 GPa) than calcite fibres (H=0–3 GPa; E=20–60/80 GPa). Thus, brachiopods with calcite semi-nacre can cement to a substrate and remain immobile during their adult life cycle. This correlation between mode of life and material properties, as a consequence of ultrastructure, begins to explain why organisms produce a wide range of structures using the same chemical components, such as calcium carbonate.