GOALI: Stimulated Raman microscopy for sensitive real-time detection of membrane fouling

膜提供了一种选择性屏障或过滤器，允许某些化合物通过，但阻止其他化合物通过。膜将盐从海水中分离出来生产饮用水。在排放控制中，膜防止污染物被释放到环境中。在垃圾填埋场，膜阻止污染物渗入地下水。然而，在过滤污染物的过程中，某些化合物的滞留会导致污染。在依赖膜的净化过程中，污垢是一个严重且普遍存在的问题，因为它降低了膜的性能，增加了能量消耗，并可能导致膜的永久性损坏。综上所述，这些影响增加了膜操作的成本，因此，污染缓解是工业膜工艺的重大兴趣。缓解策略的一个关键部分是检测，以便在污染未受控制之前主动防止污染。现有的检测技术依赖于大量测量，例如膜上的压降，这可以提供污染的早期预警。然而，这些散装技术不能提供导致结垢的具体化学信息。预计化学鉴定可以促进抗污染膜的分子水平设计。该研究将展示一种在实际操作条件下检测膜污染的创新方法。这项工作将展示一种有效、高分辨率、无标签、非破坏性和非侵入性的实时方法，用于在实际操作条件下进行污垢检测。将回答一些基本问题，包括所提出的光学检测方法对早期反渗透、结垢起始和生长的敏感性，这表现为横向和厚度尺寸的增加。该研究是一个跨越物理学、材料科学和工程学的跨学科课题。如果成功，该项目将使反渗透海水淡化系统的效率更高，成本更低；并将为其他基于膜的分离应用提供类似的显著优势。该项目将为研究生和本科生提供研究机会，并通过参与公共科学演示、实验室参观、K-12课程以及参与电气、计算机和能源工程小组，向学院和K-12级别的代表性不足的学生传播信息。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。

A membrane provides a selective barrier or filter, allowing certain compounds to pass through but preventing others. Membranes separate salts from sea water to produce drinking water. In emissions control, membranes prevent pollutants from being released into the environment. In landfills, membranes stop contaminants from leaching into the groundwater. In the process of filtering contaminants, however, the retention of certain compounds can lead to fouling. Fouling is a serious and ubiquitous problem in purification processes that rely on membranes, as it decreases membrane performance, increases energy consumption, and can lead to permanent damage of the membrane. Combined, these effects increase the cost of membrane operation, and thus, fouling mitigation is of great interest for industrial membrane processes. A key part of the mitigation strategy is detection, in order to proactively prevent fouling before it proceeds unchecked. Existing detection techniques rely on bulk measurements, such as pressure drop across the membrane, which can give an early warning of fouling. However, these bulk techniques do not provide chemical specific information on what leads to fouling. It is anticipated that chemical identification could facilitate molecular-level design of membranes that are resistant to fouling. The research will demonstrate an innovative method to detect membrane fouling under realistic operating conditions. The work will demonstrate an effective, high-resolution, label-free, non-destructive, and non-invasive real-time method for fouling detection under realistic operating conditions. A number of fundamental questions will be answered, including the sensitivity of the proposed optical detection method to early-stage reverse-osmosis, scaling initiation and growth as manifested by an increase in lateral and thickness dimensions. The research is an interdisciplinary topic spanning physics, materials science and engineering. If successful, the project will enable higher efficiency and lower-cost operation of reverse-osmosis desalination systems; and will provide similar significant benefits for other membrane-based separation applications. The project will provide research opportunities for graduate and undergraduate students, as well as dissemination to under-represented students at the college and K-12 level through involvement with public scientific demonstrations, laboratory tours, K-12 courses, and involvement with the Women in Electrical, Computer and Energy Engineering group.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.