RAPID: Characterization of the shear stress enhanced electric field gradients in MOF/Polymers composite thin films and multilayered fibers.

非技术总结：该RAPID项目由材料研究部固态和材料化学项目支持，重点是基础研究，旨在提高我们对具有纳米级过滤能力的材料的认识，这些材料可能应用于开发更耐用、更易于磨损的呼吸器。由于目前的冠状病毒（COVID-19）大流行，这种类型的研究变得必要，其中生命损失，经济生计减少和生活质量下降只是已经显现的后果中的一小部分。为了重新获得安全的生活和工作环境，需要的主要物品之一是个人防护装备，如口罩和呼吸器。不幸的是，世界范围内的防护装备短缺导致了这些防护装备的过度重复使用，这往往不仅损害了佩戴者的利益，也损害了其他人的利益。此外，由于固有的大压力梯度和相对较低的水蒸气透射率，呼吸器对大多数人来说戴起来也不舒服。该项目为从事过滤介质开发和应用的学术界和工业界的研究人员提供了具体的调整程序，从而通过改善我们的健康、生活和环境条件来促进社会福利。除了个人防护设备，更好的纳米级过滤介质的好处也延伸到应用，包括水膜处理，纳米反应器和化学催化。该项目涉及来自不同社会经济和教育水平的学生，由于其跨学科的性质，他们获得了涉及化学、工程、物理和材料科学等方面的知识和研究经验。技术摘要：在材料研究部固态和材料化学项目的支持下，这个RAPID研究项目的重点是从根本上表征复合聚合物/金属有机框架（MOFs）薄膜和多层电纺丝纤维材料中可变剪切应力增强的局部电场梯度。首席研究员和她的研究小组研究具有较大电场梯度（EFGs）的材料是否具有优越的过滤/吸附性能。一般来说，复合聚合物的过滤性能可以通过改变其表面形态（直径、表面粗糙度等）来调节，而实现这一目标的一种方法是加入mof。为了进一步提高纳米过滤性能，必须增强静电特性，本项目通过使用可变纯粹应力来定向排列和增强局部电场梯度来实现这一目标。多核（1H， 2H和17O）磁共振（NMR）和扫描电子显微镜（SEM）提供了各种聚合物之间以及mof和聚合物之间的局部相互作用的信息。电场梯度的信息是通过四极2H和17O核获得的，它们的大小与施加的剪切应力的程度相关。研究了聚合物的类型、结晶度和形态，以及不同MOF类型和含量以及用于构建多层纤维复合材料的层序。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical Summary: This RAPID project, supported by the Solid State and Materials Chemistry Program in the Division of Materials Research, is focused on fundamental investigations, aimed at advancing our knowledge about materials with nanoscale-level filtration capabilities that have possible applications in the development of longer lasting respirators with increased ease-of-wear. This type of research has become necessary due to the current coronavirus (COVID-19) pandemic, of which the loss of lives, reduced financial livelihoods and reduced quality of lives are just a few of the already manifested consequences. In order to regain safe living and working environments, one of the main things needed is personal protective equipment such as facemasks and respirators. Unfortunately, there are worldwide shortages which have resulted in excessive reuse of these protective equipment, oftentimes to the detriment of not only the wearer, but others. Additionally, respirators are also uncomfortable to wear for most people, due to the inherent large pressure gradients and relatively low water vapor transmission. This project provides researchers in academia and industries involved in the development and application of filtration media with specific tuning procedures, which will in turn advance the welfare of society through improvements in our health, living and environmental conditions. Beyond personal protective equipment, the benefits of better nanoscale filtration media also extend to applications including water membrane treatments, nanoreactors, and chemical catalysis. The project involves the participation of students from various socioeconomic and education levels, and because of its interdisciplinary nature, they gain the knowledge and research experience involving aspects of chemistry, engineering, physics and material science. Technical Summary: With support from the Solid State and Materials Chemistry Program in the Division of Materials Research, this RAPID research project focuses on fundamentally characterizing the variable shear stress enhanced local electric field gradients in composite polymers/metal organic frameworks (MOFs) thin films, and multilayered electrospun fibrous materials. The principal investigator and her research group study whether materials that have greater electric fields gradients (EFGs) exhibit superior filtration/adsorption properties. Generally, the filtration properties of composite polymers can be tuned by modification of their surface morphology (diameter, surface roughness, etc.) and one way to accomplish this is by the incorporation of MOFs. To further increase nano-filtration properties, the electrostatic characteristics must be enhanced, and this project accomplishes this by the directional alignment and enhancement of the local electric field gradients using variable sheer stresses. Multinuclear (1H, 2H, and 17O) Magnetic Resonance (NMR) and Scanning Electron Microscopy (SEM) provide information about the local interactions between the various polymers, as well as between the MOFs and the polymers. Information about the electric field gradients is accessed through the quadrupole 2H and 17O nuclei and their magnitudes correlated with the degree of shear stress applied. Polymer type, crystallinity and morphology are also investigated, along with different MOF types and content as well as the order of layering used to construct the multilayered fibrous composites.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.