Materials World Network: Particle-Mediated Control Over Crystallization: From the Pre-Nucleation Stage to the Final Crystal

材料世界网络：粒子介导的结晶控制：从预成核阶段到最终晶体

• 批准号: 1312697
• 负责人: Jillian Banfield
• 金额: $ 41.71万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1312697&HistoricalAwards=false
• 关键词: Materials; World; Network; Particle; Mediated

TECHNICAL SUMMARY:The formation of hierarchically organized crystalline solids through nanoparticle interaction and attachment is now recognized as a widespread phenomenon in environmental, biological and synthetic crystallization systems. The goal of this project is to develop a mechanistic understanding of how these so-called mesocrystals are created through particle-mediated growth processes. To achieve that goal, expertise in growth of mesocrystals will be combined with capabilities in high-resolution in situ transmission electron microscopy (TEM) and atomic force microscopy (AFM) imaging, dynamic force spectroscopy (DFS) of nanoparticle interactions, determination of atomic structure, and modeling and simulation from the atomic to mesoscale. Using calcium carbonate, iron oxide and calcium-silicate hydrate (SCH) combined with polymers as the experimental systems, the project will pursue three thrusts, structured around the key scientific issues. The nature of pre-nucleation clusters will be determined using ion potential measurements, titration and ultracentrifugation and their solution interaction dynamics will be probed through liquid cell TEM. The interactions responsible for particle co-orientation and reorientation will be determined through a combination of DFS and modeling. Experimental measurements will be supported by molecular modeling simulations, which will be used to determine molecular details of the effective interactions and provide parameters for phase field calculations. The kinetics of particle aggregation, crystallographic orientations of the aggregating particles, and structural evolution of mesocrystalline aggregates will be investigated by liquid cell TEM and ex situ HRTEM. Emphasis will be placed on distinguishing between oriented attachment and orientation following random aggregation either through whole-particle rotation or atomic-scale ripening. These data will be compared to phase-field models of assembly that utilize the experimentally determined interaction energies. The outcome will be a set of principles to guide synthetic strategies for creating hierarchically organized materials such as bioceramics, photonic solids, energy harvesting materials.NON-TECHNICAL SUMMARY:Through support from the NSF Division of Materials Research, a Materials World Network will be formed to investigate mechanisms by which complex crystalline structures, known as mesocrystals, are created through the interaction and attachment of nanoparticles. The goal of this research is to establish a mechanistic understanding of this process and a set of principles to guide synthetic strategies for creating hierarchically organized materials such as bioceramics, photonic solids, and energy harvesting materials. The work will be carried out by combining computer simulations and chemical analyses with a powerful set of in situ microscopy tools that provide real-time molecular-scale information about both nanoparticle attachment processes and the interaction forces between the particles. The materials to be investigated include those of relevance to biomaterials research, such as calcium carbonate, as well as those of relevance in energy and environmental systems such as iron oxide. The outcome will be a set of physical principles that can be applied both to understanding the processes responsible for formation of natural materials in the environment and to synthesis of hierarchical materials for energy, biomedical, and structural applications. Success of the project is enabled by an international collaboration between four US and German Universities, each of which brings a unique set of skills and knowledge to the project. Moreover, this collaboration will provide a unique learning experience for the graduate and undergraduate students involved in the research through international exchanges between the US and German labs. Finally, the project will include development of a module on mesocrystal formation for the public outreach programs to be made available through the NSF-funded Nanoscale Informal Science Education network.

通过纳米颗粒相互作用和附着形成分级组织的结晶固体现在被认为是环境、生物和合成结晶系统中的普遍现象。 这个项目的目标是发展一个机械的理解，这些所谓的介晶是如何通过粒子介导的生长过程。 为了实现这一目标，介晶生长的专业知识将与高分辨率原位透射电子显微镜（TEM）和原子力显微镜（AFM）成像，纳米颗粒相互作用的动态力光谱（DFS），原子结构的测定以及从原子到介观尺度的建模和模拟的能力相结合。 使用碳酸钙，氧化铁和硅酸钙水合物（SCH）与聚合物结合作为实验系统，该项目将围绕关键科学问题进行三个重点。 预成核簇的性质将使用离子电位测量，滴定和ultracenthegation和它们的溶液相互作用动力学将通过液体细胞TEM探测。 将通过DFS和建模的组合来确定负责颗粒共取向和重取向的相互作用。 实验测量将得到分子建模模拟的支持，这将用于确定有效相互作用的分子细节，并为相场计算提供参数。 颗粒聚集的动力学、聚集颗粒的结晶取向以及介晶聚集体的结构演变将通过液池TEM和非原位HRTEM进行研究。 重点将放在区分定向附着和定向后随机聚集无论是通过整个粒子旋转或原子尺度的成熟。 这些数据将进行比较，利用实验确定的相互作用能的组装相场模型。 结果将是一套原则，以指导合成策略，创造分层组织的材料，如生物陶瓷，光子固体，能量收集材料。非技术摘要：通过支持美国国家科学基金会材料研究部，材料世界网络将形成调查机制，其中复杂的晶体结构，称为介晶，通过纳米粒子的相互作用和附着创建。 这项研究的目标是建立对这一过程的机械理解和一套指导合成策略的原则，以创建分层组织的材料，如生物陶瓷，光子固体和能量收集材料。 这项工作将通过将计算机模拟和化学分析与一套强大的原位显微镜工具相结合来进行，这些工具提供了有关纳米颗粒附着过程和颗粒之间相互作用力的实时分子尺度信息。 待研究的材料包括与生物材料研究相关的材料，如碳酸钙，以及与能源和环境系统相关的材料，如氧化铁。 其结果将是一套物理原理，可用于理解环境中天然材料形成的过程，以及用于能源，生物医学和结构应用的分层材料的合成。 该项目的成功是由四所美国和德国大学之间的国际合作，其中每一个带来了一套独特的技能和知识的项目。 此外，这种合作将通过美国和德国实验室之间的国际交流，为参与研究的研究生和本科生提供独特的学习体验。 最后，该项目将包括开发一个关于介晶形成的模块，用于通过NSF资助的纳米级非正式科学教育网络提供的公共宣传计划。