Spontaneous and nonphotochemical laser-induced nucleation in levitated supersaturated microdroplets

悬浮过饱和微滴中自发和非光化学激光诱导成核

• 批准号: 0932810
• 负责人: Bruce Garetz
• 金额: --
• 依托单位: Polytechnic University of New York
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0932810&HistoricalAwards=false
• 关键词: Spontaneous; nonphotochemical; laser; induced; nucleation

0932810GaretzThis project investigats both spontaneous and laser-induced nucleation in levitated supersaturated microdroplets having diameters ranging from about 5 to 50 ìm, that corresponds to a range of volumes from 0.065 to 65 pL. The small volumes achievable in microdroplets allow the attainment of significantly higher supersaturations than in bulk solutions, creating conditions favorable for the creation of metastable polymorphs. Such microdroplets provide a means of eliminating impurity induced heterogeneous crystallization, providing a unique opportunity to study polymorph control by creating designer interfaces using surfactant molecules. The principal aim of this projectl is to study polymorph control of organic compounds in the spontaneous and laser induced nucleation of levitated supersaturated microdroplets, as a function of microdroplet volume, with and without surfactants. Surfactants will serve as designer templates for nucleation of specific polymorphs. It is anticipated that these studies will reveal unusual and even unknown polymorphs and hydrates, which will be identified by deliquescence points, Raman spectra and weight changes. The project brings together a unique combination of expertise: Garetz in the area of laser-material interactions, and Arnold in the area of microdroplet levitation, in collaboration with Michael Ward in the area of crystallization and polymorphism. It differs significantly from Garetz's earlier work on laser-induced nucleation, in that all experiments will be carried out in the confined volumes of microdroplets, and many will employ surfactants. Under these novel conditions, it is anticipated that surfactant monolayers will exert a greater influence on nucleation compared to bulk crystallization media owing to the greater surface area volume ratio in microdroplets and the minimization of interference from adventitious nucleation impurities. While other research groups have studied the effects of surface monolayers on polymorphism or the effects of confined volumes on polymorphism, the research proposed herein is unique in simultaneously combining these two parameters into a single experiment in an ultraclean environment, in a manner that allows independent control of each parameter. Broader Impact: Although nucleation of crystalline materials has been investigated for decades, it remains a poorly understood phenomenon that will only be unraveled through new and innovative methods. If this project succeeds it will open considerable opportunities for exploring the nucleation, crystallization, and polymorphism of innumerable organic compounds that are interesting because of their commercial applications. New polymorphs represent new materials. The methodology developed in this proposal may provide a unique approach to the discovery of new polymorphs, which is of vital importance in the development of new pharmaceuticals. If this project is successful, it could potentially transform the way new polymorphs are discovered in the pharmaceutical industry. Both PIs of this proposal have considerable experience mentoring undergraduate students, and the proposed research lends itself to such training through summer research internships, funding for which is requested in this proposal.

0932810Garetz该项目研究了悬浮过饱和微滴中的自发成核和激光诱导成核，悬浮过饱和微滴的直径约为5至50？m，对应的体积范围为0.065至65 Pl。微滴中可实现的小体积允许获得比在整体溶液中高得多的过饱和度，从而为亚稳态多晶型的产生创造了有利条件。这种微滴提供了一种消除杂质诱导的异质结晶的方法，通过使用表面活性剂分子创建设计者界面，为研究多晶型控制提供了独特的机会。本项目的主要目的是研究有机化合物在悬浮过饱和微滴自发成核和激光诱导成核过程中的晶型控制，作为微滴体积的函数，在有和没有表面活性剂的情况下。表面活性剂将作为特定多晶型成核的设计模板。预计这些研究将揭示不寻常的、甚至未知的多晶型和水合物，它们将通过潮解点、拉曼光谱和重量变化进行鉴定。该项目汇集了独特的专业知识组合：Garetz在激光-材料相互作用领域，Arnold在微滴悬浮领域，与Michael Ward在结晶和多晶性领域合作。它与Garetz早期关于激光诱导成核的工作有很大的不同，因为所有的实验都将在受限体积的微滴中进行，并且许多实验将使用表面活性剂。在这些新的条件下，由于微滴的表面积体积比更大，外来成核杂质的干扰最小，预计表面活性剂单分子膜将比大块结晶介质对成核产生更大的影响。虽然其他研究小组已经研究了表面单分子层对多态的影响或限制体积对多态的影响，但这里提出的研究是独一无二的，它将这两个参数同时结合到超净环境中的单个实验中，以允许独立控制每个参数的方式。更广泛的影响：尽管结晶材料的成核已经被研究了几十年，但它仍然是一个鲜为人知的现象，只有通过新的和创新的方法才能解开。如果这个项目成功，它将为探索无数有机化合物的成核、结晶和多态提供相当大的机会，这些有机化合物因其商业应用而令人感兴趣。新的多晶型代表了新的材料。该提案中开发的方法学可能为发现新的多态提供一种独特的方法，这在新药的开发中至关重要。如果这个项目成功，它可能会改变制药业发现新多态的方式。这项建议的两位私人投资主任都有指导本科生的丰富经验，建议的研究通过暑期研究实习来进行这种培训，这项建议要求提供资金。