International Research Fellowship Program: Shear-perturbed Polymer Structure and Dynamics through NMR Spectroscopy and Rheo-NMR

0753559Brown国际研究奖学金计划使美国科学家和工程师能够在国外进行九到二十四个月的研究。 该项目的奖项为联合研究以及使用国外独特或互补的设施、专业知识和实验条件提供了机会。该奖项将支持 Jennifer R. Brown 博士与新西兰惠灵顿大学的 Paul Callaghan 博士合作为期 18 个月的研究奖学金。核磁共振 (NMR) 光谱与流变核磁共振相结合，用于研究聚合物分子顺序和响应机械变形的动力学。 核磁共振技术具有独特的能力，可以通过空间分辨率将宏观材料响应与光谱技术的微观分子现象联系起来。 由于生物学、食品和材料加工、采油和生物技术应用中存在许多复杂的流体，机械响应的分子基础最近引起了人们的兴趣。 Rheo-NMR 的使用为研究此类系统中的分子动力学提供了独特的视角，因为剪切池包含在 NMR 波谱仪内，并且可以在运动时研究样品。 使用高分辨率窄间隙圆柱形库埃特剪切池，其具有足够高的剪切速率以中断氢键。 对于缔合碳水化合物透明质酸，剪切对构象的影响已使用 13C NMR 得到证明，这强烈表明在其他缔合多糖中也可以观察到类似的效果，并激发了流变核磁共振和光谱学在研究具有预先指定光谱的蛋白质（例如胰岛素）方面的潜力。 这项利用核磁共振波谱技术对剪切扰动蛋白质和多糖进行的研究试图确定负责分子间相互作用及其相关反应速率的位点。 蛋白质分子动力学和结构的核磁共振研究有可能改善现代聚合材料的设计和加工，例如创造质地更好的食物或更好地了解生物学上重要的流体特性。 由于蛋白质结构与功能相关，因此了解流变学对结构的影响可能产生的科学影响涵盖生物学、化学和材料科学等领域。因此，拟议的研究具有高度跨学科的性质，这增加了跨领域的合作和交流。

0753559BrownThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support an eighteen month research fellowship by Dr. Jennifer R. Brown to work with Dr. Paul Callaghan at the University of Wellington in New Zealand.Nuclear Magnetic Resonance (NMR) spectroscopy, in combination with Rheo-NMR, is being used to study polymer molecular order and dynamics in response to mechanical deformation. NMR techniques have the unique ability to connect macroscopic material responses through spatial resolution to microscale molecular phenomena via spectroscopic techniques. The molecular basis for the mechanical response has been of recent interest since there are many complex fluids in biology, food and material processing, oil recovery and biotechnology applications. The use of Rheo-NMR offers a unique perspective in the investigation of the molecular dynamics in such systems, since the shear cell is contained within the NMR spectrometer and the sample may be studied while in motion. A high resolution narrow gap cylindrical Couette shear cell is used with the capacity for high enough shear rates that hydrogen bonds should be interrupted. For the associating carbohydrate hyaluronan, the influence of shear on conformation has been proven using 13C NMR, which strongly suggests that similar effects can be observed in other associating polysaccharides, and encourages the potential of Rheo-NMR and spectroscopy in investigating proteins with a pre-assigned spectra, such as insulin. This study of shear-perturbed proteins and polysaccharides with NMR spectroscopic techniques attempts to identify the sites responsible for inter-molecular interactions and their associated reaction rates. NMR studies of protein molecular dynamics and structure have the potential to improve the design and processing of modern polymeric materials, such as creating food with better texture or to better understand biologically important fluid properties. Since protein structure is related to function, the possible scientific impacts of understanding the rheological effect on structure spans fields ranging from biology to chemistry and materials science. The proposed research is therefore of a highly inter-disciplinary nature, which increases collaboration and communication across fields.