Microstructural Evolution of Molecular Crystals

该奖项的研究目标是开发与实验相结合的探测数值方法，以预测分子晶体颗粒在微米和亚微米尺度上的机械响应。在制药和食品工业中，这种类型的材料在制造过程中需要进行机械研磨，以减小颗粒尺寸。在这一过程中，机械应力在晶格中产生结构变化，经常影响药物产品的关键性质，如稳定性和溶出度。本项目中提出的理论和实验将提供关于由于微观颗粒中的高表面积体积比而导致的晶体缺陷与表面相互作用的信息，并将朝着在晶体材料的一般数值模拟中集成微观机制迈出一步。拟议的研究涉及以下任务：(1)利用物理和化学分析表征技术，包括光谱分析，热分析，和表面方法，以更好地了解和控制缺陷和相互作用(2)机械试验(3)机械载荷下颗粒变形的数值模拟。该项目将为理解分子晶体在食品和药品加工过程中的演化做出重要贡献。如果成功，拟议的数值和实验工作将对研磨过程中对有害变化不那么敏感的材料的开发以及食品和制药行业的操作配方和质量控制的优化产生影响。这项工作的结果将被整合到普渡大学工程和制药科学的本科生和研究生课程中，因此，将影响新一代工程师和制药科学家的形成，他们具有多学科形成和成功合作项目的能力。

The research objective of this award is to developrobust numerical methods in coordination with experiments to predict the mechanical response of molecular crystal particles at the micron and submicron scales.In pharmaceutical and food industries,this type ofmaterialis subjected to mechanical milling during manufacturing to reduce particle size. During this processmechanical stresses produce structural changes in the crystal latticethatoften affect key properties of drug products, such as stability and dissolution rates.The theory and experiments proposed in this project will provide information about the interaction of crystalline defects with surfaces due to the high surface to volume ratio in microscopic particles and will be a step toward the integration of microscopic mechanisms in the numerical modeling of crystalline materials in general.The proposed research involves the following tasks, (1) Experimental approach to detect disorder in milled materials using physical and chemical analytical characterization techniques including spectroscopy, thermal, and surface methods to better understand and control defects and interactions (2) Mechanical testing (3) Numerical simulations of deformation of particles under mechanical loading. This project will make important contributions towardsthe understanding of the evolution of molecular crystals during food and drug processing. If successful, the proposed numerical and experimental effort will have an impact in the development of materials less sensitive to detrimental changes during milling processingas well as in the optimization of operational formulations and quality control in food and pharmaceutical industries.The results of this work will be integrated into the undergraduate and graduate curriculum in Engineering and Pharmaceutical Sciences at Purdue and therefore, will influence the formation of new generations of engineers and pharmaceutical scientistswith a multidisciplinary formation and with the ability to successfully work in collaborative programs.