Accelerated Reactions in Droplets and Thin Films: Surface Effects and Analytical Implications

在化学系化学测量和成像计划的支持下，普渡大学的格雷厄姆·库克斯教授和他的团队正在努力解释和利用一个令人震惊但简单的事实：许多化学反应的速度随着反应混合物的体积减少而急剧增加。正因为如此，在微滴中的反应可以很容易地比在罐子、桶或工业大桶中的相同反应快数千倍。这可能会提供一种替代使用昂贵的化学催化剂的方法，以节省时间和能源。Cooks小组的研究重点是了解液滴界面在加速反应中的作用，特别是那些在各种分析测量中有用的反应。其他潜在的应用包括研究药物的保质期，以及详细检查活细胞内发生的快速生化反应。该项目提供先进仪器和精密化学测量方面的培训，并培养研究生在与工业和国家安全关系密切的领域为美国劳动力做出贡献。将采用一系列方法来转移研究结果并加强该计划的培训方面，包括强烈的产业互动、有重点的短期培训课程、将本科生纳入研究，以及由在分析化学方面有实力的地区机构参与的合作研究努力。这项建议的研究目标是发现和表征利用加速反应(包括衍生化)进行液滴和其他受限体积中的化学分析的方法，并阐明提高反应速率常数的机制。对机理知识的探索集中在表面与本体反应作为液滴大小和试剂浓度函数的动力学研究上。质谱学可以从这些反应中受益，也可以探测这些反应。它是主要的测量工具，与界面振动光谱一起使用。其他目标应用程序来自学术和工业环境。例如，涉及非共价氨基酸簇的化学反应和多肽键的形成。这一奖项反映了NSF的法定使命，并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，被认为值得支持。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Graham Cooks and his group at Purdue University are working to explain and exploit a startling but simple fact: the speed of many chemical reactions increases dramatically as the volume of the reacting mixture decreases. Because of this, reactions in microdroplets can easily be thousands of times faster than the same reactions in jars, barrels or industrial vats. This may offer an alternative to the use of expensive chemical catalysts to save time and energy. Research in the Cooks group is focused on understanding the role of the droplet interface in accelerating reactions, particularly those that are useful in various analytical measurements. Among other potential applications are studies of the shelf life of pharmaceuticals, and detailed examination of fast biochemical reactions that occur within living cells. The project provides training in advanced instrumentation and precision chemical measurements, and prepares graduate students to contribute to the US workforce in a field with strong industrial and national security ties. A range of methods will be deployed to transfer the results of the research and strengthen the training aspect of the program, including strong industrial interactions, focused short training courses, inclusion of undergraduates in research, and collaborative research efforts involving regional institutions with strength in analytical chemistry.The research objectives of this proposal are to discover and characterize ways to exploit accelerated reactions (including derivatization) for chemical analysis in droplets and other confined volumes, and to elucidate the mechanisms that increase reaction rate constants. The search for mechanistic knowledge focusses on kinetic studies of surface vs. bulk reactions as a function of droplet size and reagent concentration. Mass spectrometry can benefit from as well as probe these reactions. It is the main measurement tool, along with interfacial vibrational spectrometry. Other target applications come from both academic and industrial settings. Examples include chemical reactions involving non-covalent clusters of amino acids and peptide bond formation.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.