EAGER: Exploring the Application of Transition Zone Theory to Crystallization from Solutions

EAGER：探索过渡区理论在溶液结晶中的应用

• 批准号: 1950984
• 负责人: James Martin
• 金额: $ 15万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-15 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1950984&HistoricalAwards=false
• 关键词: EAGER; Exploring; Application; Transition; Zone

Part I: Non-Technical SummaryCrystallization was one of the earliest chemical processes studied by humans, as indicated by evidence of the practice of salt crystallization from seawater in pre-historic times. Today, the ability to control crystal growth is essential to technological devices such as solar cells and lasers as well as in preparation of pharmaceutical agents. However, the fundamental mechanisms underlying crystal growth are not fully understood. Classical nucleation theory, which is the widely accepted model for how crystals grow, does not fully account for experimental measurements. In this project, supported by the Solid State and Materials Chemistry program within the Division of Materials Research, the PI will continue to develop a new model of crystal growth initiated in his laboratory for formation of crystals from molten materials. The new project extends this theory to crystal growth from solutions by studying the arrangement of starting materials in the solutions and the speeds at which solid crystals form under varying conditions. Taken together, these experiments will increase understanding of crystal growth, eventually allowing scientists to develop better procedures for growing high-quality crystals for applications. The project also encompasses training of students and postdoctoral researchers, including their participation in advanced experiments at national synchrotron facilities. Part II: Technical SummaryThe recently developed Transition Zone Theory of crystallization, based on the cooperativity of crystallizing units rather than a classical particle attachment/detachment conception, accurately describes the crystal growth rates from melts of diverse materials. This project, supported by the Solid State and Materials Chemistry program within the Division of Materials Research, tests the hypothesis that similar entropic and cooperative influences are responsible for controlling crystallization from solution. This work extends the model to encompass crystallization from solution by studying the kinetics of crystal growth across binary phase diagram systems to determine the respective activation energy requirements to form long-range order in crystals and to exclude solvent from the crystallizing solute.Using representative systems of hydrated metal salts and aromatic organic molecules, the project uses spectroscopic and diffraction methods to investigate 1) the structure of saturated solutions, 2) comparative crystallization rates as a function of solvent/solute concentration from the pure phase to eutectic compositions, and 3) comparative rates of crystallization out of diverse solvents for which strong solvent-solute interactions are likely to inhibit crystallization. The long-term goal is that an extension of the Transition Zone Theory model can provide the basis for a comprehensive mechanistic understanding of crystal growth across a continuum of systems from pure metals to saturated solutions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

第一部分：非技术摘要 史前时期从海水中盐结晶的实践证据表明，结晶是人类最早研究的化学过程之一。 如今，控制晶体生长的能力对于太阳能电池和激光器等技术设备以及药剂的制备至关重要。 然而，晶体生长的基本机制尚未完全了解。 经典成核理论是广泛接受的晶体生长模型，但它并不能完全解释实验测量。 在该项目中，在材料研究部的固态和材料化学项目的支持下，首席研究员将继续开发在他的实验室中启动的一种新的晶体生长模型，用于从熔融材料形成晶体。 新项目通过研究溶液中起始材料的排列以及不同条件下固体晶体形成的速度，将该理论扩展到溶液中的晶体生长。 总而言之，这些实验将增进对晶体生长的理解，最终使科学家能够开发出更好的程序来生长高质量的晶体以供应用。 该项目还包括对学生和博士后研究人员的培训，包括他们参与国家同步加速器设施的高级实验。 第二部分：技术摘要最近开发的结晶过渡区理论基于结晶单元的协同性而不是经典的颗粒附着/分离概念，准确地描述了不同材料熔体的晶体生长速率。 该项目由材料研究部的固态和材料化学项目支持，测试了类似的熵和协同影响负责控制溶液结晶的假设。 这项工作通过研究二元相图系统中晶体生长的动力学，确定在晶体中形成长程有序以及从结晶溶质中排除溶剂的各自活化能要求，将模型扩展到包括从溶液中结晶。使用以下代表性系统水合金属盐和芳香族有机分子，该项目使用光谱和衍射方法来研究 1) 饱和溶液的结构，2) 从纯相到共晶的溶剂/溶质浓度函数的比较结晶速率组合物，以及 3) 从不同溶剂中结晶出来的比较速率，对于这些溶剂，强的溶剂-溶质相互作用可能会抑制结晶。 长期目标是过渡区理论模型的扩展可以为从纯金属到饱和溶液的连续体系中晶体生长的全面机理理解提供基础。该奖项反映了 NSF 的法定使命，并被认为是值得的通过使用基金会的智力优势和更广泛的影响审查标准进行评估来获得支持。

项目成果

Reply to “A Comparison of the Stochastic and Deterministic Approaches in a Nucleation–Growth Type Model of Nanoparticle Formation”

回复“成核过程中随机方法和确定性方法的比较”纳米粒子形成的生长类型模型

• DOI: 10.1021/acs.chemmater.1c01690
• 发表时间: 2021
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: Martin, James D.