Biomimetic Composites With Amorphous Calcium Carbonate: Linking Microstructure to Mechanical Response

无定形碳酸钙仿生复合材料：将微观结构与机械响应联系起来

• 批准号: 1435920
• 负责人: Rosa Espinosa-Marzal
• 金额: $ 39.95万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1435920&HistoricalAwards=false
• 关键词: Biomimetic; Composites; Amorphous; Calcium; Carbonate

Recent discoveries have revealed that many organisms produce amorphous calcium carbonate not as a precursor for more stable calcite but as a mineral of choice. The crucial role of amorphous calcium carbonate in morphological and structural control of biominerals has thus been recognized. However, the determining factors for the formation, stabilization and transformation of the amorphous phase are still in debate and the mechanical response of the resulting composite has not been investigated yet. This award supports fundamental research to investigate the mechanical response of amorphous-crystalline organic calcium carbonate composites as a function of the microstructure using a combination of experimental and modeling work. Tuning and optimizing the mechanical properties of this material opens new opportunities for the development of biomimetic materials with superior properties. In parallel, this research addresses major questions regarding biomineralization, a topic of primary biogeochemical, environmental, and economic significance. This research involves several disciplines including mechanics, engineering, materials science, colloidal science, and chemistry. This multi-disciplinary approach provides a wide range of research opportunities. It will help broaden participation of underrepresented groups through several undergraduate students in the involved research groups and a K-12 Outreach program offering introductory lectures, field trips, and hands on research. The knowledge gained in this project will be integrated in various lectures and therefore it will positively impact engineering education. The biomimetic composites with amorphous calcium carbonate are synthesized in the laboratory. This research aims at establishing design parameters to tune their microstructure, to scrutinize their microstructure-mechanical response relationship, and to study their failure mechanisms. The experimental work involves adsorption and force measurements to study mineral formation, nanoindentation to study microstructure-mechanical response relationship and atomic force microscopy to investigate interfacial properties and amorphous-to-crystalline transformation. The modeling work is based on the Shear Transformation Zone Theory, a statistical thermodynamic framework for modeling failure deformation in amorphous materials, and cohesive finite element simulations. Correlation between experiments and modeling will enable to uncover fundamental phenomena underlying the mechanical response of the novel hybrid composites including (i) multiscale toughness mechanisms through a combination of hierarchical geometry and microstructure design, (ii) transition from ductile behavior with distributed deformation to brittle response and strain localization, (iii) glass transition, and (iv) interfacial separation and healing.

最近的发现表明，许多生物体产生的无定形钙不是作为更稳定的方解石的前体，而是作为选择的矿物。因此，已经认识到了碳酸钙在生物矿物质的形态和结构控制中的关键作用。但是，尚未研究形成，稳定和变形的决定因素，仍在争论中，并且尚未研究所得复合材料的机械响应。该奖项支持基本研究，以研究碳酸盐钙复合材料的机械响应，并使用实验和建模工作的组合来研究微观结构。调整和优化该材料的机械性能为开发具有优质特性的仿生材料开发了新的机会。同时，这项研究解决了有关生物矿化的主要问题，这是主要的生物地球化学，环境和经济意义的话题。这项研究涉及几个学科，包括力学，工程，材料科学，胶体科学和化学。这种多学科方法提供了广泛的研究机会。这将有助于通过参与研究小组中的几名本科生和K-12外展计划扩大代表性不足的小组的参与，提供介绍性的讲座，实地考察和动手研究。该项目获得的知识将集成到各种讲座中，因此将对工程教育产生积极影响。 具有碳酸钙的仿生复合材料在实验室中合成。这项研究旨在建立设计参数以调整其微观结构，仔细检查其微观结构机械响应关系并研究其故障机制。实验工作涉及研究矿物形成的吸附和力量测量，纳米指标研究微观结构机械响应关系和原子力显微镜，以研究界面特性和非定形至晶体转化。该建模工作基于剪切变换区理论，这是一个用于建模无定形材料中故障变形的统计热力学框架，以及有限的有限元模拟。 Correlation between experiments and modeling will enable to uncover fundamental phenomena underlying the mechanical response of the novel hybrid composites including (i) multiscale toughness mechanisms through a combination of hierarchical geometry and microstructure design, (ii) transition from ductile behavior with distributed deformation to brittle response and strain localization, (iii) glass transition, and (iv) interfacial separation and healing.