Microstructure of brachiopod shells - An inorganic/organic fibre composite with nanocrystalline protective layer
Microstructure of brachiopod shells - An inorganic/organic fibre composite with nanocrystalline protective layer
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腕足动物壳的微观结构——具有纳米晶保护层的无机/有机纤维复合材料
DOI：
10.1557/proc-844-y9.3
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
U. Brand
中科院分区：
文献类型：
--
作者：
E. Griesshaber;W. Schmahl;R. Neuser;R. Job;M. Bluem;U. Brand
我们利用 SEM、电子背散射衍射和显微硬度压痕研究了现代方解石腕足动物 Megerlia truncata (Linnaeus) 和 Terebratalia transversa (Sowerby) 的超微结构。外部的主壳层可以被视为纳米晶体薄膜，它在内部的、更软的第二层周围形成坚硬的保护涂层，可以表示为无机/有机纤维复合材料。次级壳层晶体的纤维状、弯曲生长发生在垂直于方解石<0 0 0 1>三重对称方向的任意方向上，并且最有可能是通过简单限制到蛋白质鞘而不是通过生物分子吸附物阻止任何特定晶面的生长来获得。纤维的曲率是由生长过程中分泌细胞阵列的重新排列引起的，从而现有的晶格不会扭曲。它充当持续晶体生长的基材。因此，生物介导的方解石结晶是一个有目的的过程，并且似乎与方解石的无机结晶显着不同。
We investigated the ultrastructure of the modern calcitic brachiopods Megerlia truncata (Linnaeus) and Terebratalia transversa (Sowerby) with SEM, electron backscattering diffraction and microhardness indentation. The outer, primary shell layer can be regarded as a nanocrystalline thin film that forms a hard protective coating around the inner, much softer secondary layer that can be expressed as an inorganic/organic fibre composite. The fibrous, curved growth of the secondary shell layer crystals occurs in arbitrary directions perpendicular to the 〈0 0 0 1〉 triad symmetry direction of calcite and is most likely obtained by simple confinement to a protein sheath rather than by biomolecular adsorbates blocking growth of any specific crystal face. The curvature of the fibres is caused by rearrangements of the secreting cell array during growth, whereby the existing crystal lattice is not distorted. It serves as a substrate for continued crystal growth. Thus biologically mediated calcite crystallization is a purposeful process and seems to be significantly different to the inorganic crystallization of calcite.