Materials World Network: Bioinspired Composite Single-Crystals - From Structural Evolution to Mechanical Characterization

技术概述：在固态和材料化学计划和材料研究部特别计划办公室的支持下，这项研究旨在对合成和生物单晶复合材料的形成、结构和机械性能产生统一的理解。材料世界网络团队由来自康奈尔大学(由材料研究部支持)、劳伦斯伯克利国家实验室和英国(利兹大学和谢菲尔德大学，由EPSRC支持)的成员组成，提供了罕见的晶体生长、生物矿化、材料合成、聚合物和胶体合成、机械性能和材料表征方面的专业知识。许多自然系统生产精细的复合材料，其中脆弱的矿物单晶和软聚合物结合在一起，创造出具有优异机械性能的材料。这种复合材料通常是根据嵌入在宿主有机基质中的均匀理想矿物晶体来理解和建模的。然而，矿物单晶本身就是被各种有机和无机材料包裹在一起的复合材料。人们对这些单晶复合材料是如何形成的或其非凡的性能知之甚少。这一国际合作的研究目标是：(1)表征单晶生物矿物，并确定它们的设计如何导致优异的机械性能；(2)将这些设计策略转化为含有小分子的方解石晶体、结构和化学上定义明确的聚合物和颗粒以及顺应性和刚性骨架，并评估所涉及的生长机制；(3)表征和模拟复合晶体的结构和机械性能，以阐明合成-结构-功能关系；以及(4)开始应用所获得的理解来合成新型复合材料。正如这项工作的灵感来自生物系统一样，所获得的见解可以用于更好地理解生物系统本身。非技术总结：在固态和材料化学计划和材料研究部特别计划办公室的支持下，这次合作汇集了来自美国和英国的经验丰富和国际公认的研究人员。这项工作的灵感来自生物矿物，它是用节能、可持续的方法形成的，具有独特的形态和优越的性能。结晶是一个非常重要的话题，它与各种现象和应用有关，从结垢、风化到生物材料、药物和纳米颗粒的生产。碳酸钙是这项提案的一个重要焦点，它本身具有巨大的工业重要性，是一种有效的碳捕获媒介。通过开发合成复合晶体的新方法，这项研究将为控制晶体材料的结构和性能提供一条普遍而简便的途径，从而获得具有定制性能的材料。这一愿景有望为人工骨和坚韧的合成牙釉质等下一代材料的合成提供基础。此外，拟议的项目将通过以下方式促进培训和教学方面的文化间交流：(1)与英国合作者进行长期和短期的个人和学生人员交流；(2)本科生的国际暑期实习，重点是接触STEM中代表性不足的少数群体；(3)由私营部门及其指定的研究人员组织的关于生物启发复合晶体的顶峰国际讲习班。PIS还将与科学教师合作，为中学生(6-8年级)制定和分发教案，重点是使用生物矿化的例子来教授科学分类和机械性能的概念。此外，该项目将促进与国家实验室和设施(例如，能源部资助的分子铸造)的对话和合作，以促进知识和能力的转让，从而使这项研究能够创造有用的技术。

TECHNICAL SUMMARY: With support from the Solid State and Materials Chemistry program and the Office of Special Programs in the Division of Materials Research, this research aims to develop a unified understanding of the formation, structure, and mechanical properties of synthetic and biologic single crystal composites. The Materials World Network team with members from Cornell University (supported by the Division for Materials Research), Lawrence Berkeley National Labs, and the UK (Universities of Leeds and Sheffield, supported by the EPSRC) offers a rare synergy of expertise in crystal growth, biomineralization, materials synthesis, polymer and colloid synthesis, mechanical properties, and materials characterization. Many natural systems produce elaborate composites in which fragile mineral single crystals and soft polymers are combined to create materials with superior mechanical properties. Such composites are typically understood and modeled in terms of homogeneous ideal mineral crystals embedded in a host organic matrix. However, the mineral single crystals are themselves composites in which a variety of organic and inorganic materials are occluded. Very little is known about how these single crystal composites form or their extraordinary properties. The research goals of this international collaboration are to: (1) Characterize single crystal biominerals and determine how their design leads to superior mechanical properties; (2) Translate these design strategies to the synthesis of calcite crystals occluding small molecules, structurally and chemically well-defined polymers and particles, and compliant and stiff frameworks, and evaluate the growth mechanisms involved; (3) Characterize and model the structural and mechanical properties of the composite crystals to elucidate synthesis-structure-function relationships; and (4) Begin to apply the understanding gained to generate novel composite materials. Just as the inspiration for this work comes from biological systems, the insights gained can be applied to better understanding the biological systems themselves. NON-TECHNICAL SUMMARY:With support from the Solid State and Materials Chemistry program and the Office of Special Programs in the Division of Materials Research, this collaboration brings together experienced and internationally-recognized researchers from the United States and Britain. The inspiration for this work comes from biominerals, which are formed using energy efficient, sustainable methods, and have unique morphologies and superior properties. Crystallization is a hugely important topic that has relevance to phenomena and applications as diverse as scaling, weathering, and the production of biomaterials, pharmaceuticals, and nanoparticles. Calcium carbonate, which is a significant focus of this proposal, is itself of tremendous industrial importance and an effective medium for carbon capture. By developing novel approaches to the synthesis of composite crystals, this research will provide a general and facile route for controlling the structure and properties of crystalline materials, leading to materials with tailored properties. This vision is anticipated to provide the basis for synthesizing next-generation materials such as artificial bone and tough synthetic dental enamel. In addition, the proposed project will promote intercultural exchanges in both training and teaching by offering: (1) Extended and short-term personnel exchanges of PIs and students with the UK collaborators; (2) International summer internships for undergraduates, with a focus on reaching under-represented minorities in STEM; and (3) a capstone international workshop on bio-inspired composite crystals organized by the PIs and their appointed researchers. The PIs will also work with science teachers to develop and distribute lesson plans for middle school students (Grades 6-8) with a focus on using examples from biomineralization to teach concepts of scientific classification and mechanical properties. In addition, this project will promote dialog and collaboration with national labs and facilities (e.g., the DOE-funded Molecular Foundry) to facilitate transfer of knowledge and capabilities for creation of useful technologies made possible by this research.