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Structure-property relationships of abiological mesocrystal in the adult sea urchin spine
——————————————————————————發表狀態：
PNAS, March 6, 2012, vol. 109, no. 10, 3699–3704
研究團隊：
Jong Seto, Yurong Ma, Helmut Cölfen .etal
研究內容：
自然界中從多尺度上進行材料的結構設計，以獲得具有獨特功能特性的材料，已成為大家廣泛應用的設計策略。本文工作對成年海膽刺進行了全面的分析，揭示了複雜的層次結構，表明了大自然如何製造一種以方解石單晶衍射而又像玻璃狀材料一樣破裂的材料。每個海膽刺都包含鎂-方解石納米晶體的高度定向陣列，其中嵌入了非晶和大分子。據推測，這種介晶結構是通過密集排列的無定形碳酸鈣(ACC)前驅顆粒的結晶形成的。ACC和/或大分子的殘留表面層保留在納米顆粒單元周圍，從而形成介晶結構且有助於斷裂行為。
Abstract
Structuring over many length scales is adesign strategy widely used in Nature to create materials with uniquefunctional properties. We here present a comprehensive analysis of an adult seaurchin spine, and in revealing a complex, hierarchical structure, show howNature fabricates a material which diffracts as a single crystal of calcite andyet fractures as a glassy material. Each spine comprises a highly orientedarray of Mg-calcite nanocrystals in which amorphous regions and macromoleculesare embedded. It is postulated that this mesocrystalline structure forms viathe crystallization of a dense array of amorphous calcium carbonate (ACC)precursor particles. A residual surface layer of ACC and/or macromoleculesremains around the nanoparticle units which creates the mesocrystal structureand contributes to the conchoidal fracture behavior. Nature’s demonstration ofhow crystallization of an amorphous precursor phase can create a crystallinematerial with remarkable properties therefore provides inspiration for a novelapproach to the design and synthesis of synthetic composite materials.