Collaborative Research: Selective Flow Through Membrane Pores with in situ Change of Wettability

合作研究：通过膜孔的选择性流动与润湿性的原位变化

• 批准号: 2012629
• 负责人: Dongjin Seo
• 金额: $ 27.3万
• 依托单位: Brigham Young University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2012629&HistoricalAwards=false
• 关键词: Collaborative; Research; Selective; Flow; Through

The goal of this project is to separate oil and water using special membranes (filters with very small pores/passages) that change how each fluid behaves at the membrane surface by applying an electric potential. The efficiency of the oil-water separation depends on the interaction of each of these components with the membrane. For example, a hydrophilic, or water-loving, membrane lets water through but rejects oil. However, the oil eventually plugs the pores, preventing additional water from moving through the membrane. This problem could be resolved if the membrane could be temporarily switched to be oleophilic, or oil-loving, to let the oil through. This switchable functionality would be especially helpful when the oil phase is valuable, such as in crude oil production where oil-water mixtures are abundant, or in the dairy industry where both the oil and water phases are valuable. Unfortunately, the ability to change membrane properties during operation is very difficult to achieve. This project will accomplish this goal by changing the surface properties of the membranes with molecules that change their orientation with electricity. First, molecules that respond to electricity and result in the desired change in hydrophilicity or oleophilicity will be identified. As an intermediate goal for this project, a membrane capable of controlling the flow of water will be developed by coating water-controlling molecules onto the membrane surface. The same will be done for oil by coating with oil-controlling molecules. Eventually, by coating both oil- and water-controlling molecules, the flow of oil and water will be controlled to separate oil-water mixtures on demand. The switchable membranes will be of societal benefit through their application in wastewater treatment, energy-efficient fuel production, dairy processes, and many others. In addition, the project will directly involve undergraduate and graduate students in impactful, transformative research. The investigators and students will, in turn, participate in rural STEM K-12 outreach programs working to develop the next generation of scientists and engineers capable of solving the problems of tomorrow. Membranes are a preferred technology for efficient oil-water separation given factors such as energy efficiency, relatively low material costs, and their demulsifying function. Membranes appear in a variety of forms constructed from different polymers or inorganic materials with added moieties that control hydrophilicity and/or oleophilicity of the membrane surfaces. However, once the surface properties of membranes are set to permeate water, they cannot be changed to permeate the oil that eventually clogs the pores. Devising a way to switch membrane functionality to and from oil- or water-permeating will mitigate fouling issues and enable collection of the oil phase. Such membrane technology would benefit many industrial applications, including enhanced oil recovery with low-salinity water flooding or the dairy industry where the oil phase is valuable. Therefore, the investigators propose a new way to selectively control water and oil flow through the membrane in situ; wettability of oil and water will be controlled through interactions with adsorbed surface molecules that change conformation with applied electric potentials. Wettability is one of the factors that control liquid flow through pores, along with the geometry and hydraulic head. Membranes that can selectively permeate only one phase at a time from oil-water mixtures will be achieved as follows: (1) First, the surface molecules that produce large changes in the contact angle of water and oil with electricity (“controlling molecules”) will be identified. The optimal hydraulic pressure and geometry with the given changes will be calculated and fabricated. (2) Next, one membrane with the optimal geometry coated with the water-controlling molecules will be prepared. The same will be prepared for oils. The separation performance of the membranes as well as the durability of surface molecules will be characterized. (3) The final project objective is to develop a membrane with "control valves" coated with two controlling molecules that modulate the wettability of oil and water simultaneously. This hybridized surface will be characterized, and membrane performance and durability will be assessed. The success of this project will enable a new approach to liquid-liquid separation and enhance the educational experiences of the undergraduate and graduate students conducting the research.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.

该项目的目的是使用特殊的膜（毛孔/通道很小的过滤器）分离油和水，以通过施加电势来改变每种流体在膜表面的表现。油水分离的效率取决于这些成分与膜的相互作用。例如，膜或热爱水的膜允许水通过，但拒绝油。但是，该油最终将杆子插入，从而防止了额外的水穿过膜。如果可以将膜暂时切换为酿酒或爱油以使油通过，则可以解决此问题。当石油阶段非常有价值时，这种可切换功能将特别有用，例如在原油生产中，油水混合物丰富，或者在油和水相的乳制品行业中都有价值。不幸的是，在操作过程中更改膜特性的能力很难实现。该项目将通过用电力改变其方向的分子来改变膜的表面特性来实现这一目标。首先，将确定对电的反应并导致所需的亲水性或油性性变化的分子。作为该项目的中间目标，通过将水控制分子涂在膜表面上，能够控制水流的膜将开发出来。通过与油控制分子涂层涂层的油也是如此。最终，通过覆盖油和水控制分子，将控制油和水的流动，​​以按需分离油水混合物。可切换的膜将通过其在废水处理，节能燃料生产，乳制品工艺等中的应用来获得社会利益。此外，该项目将直接涉及本科生和研究生参与有影响力的变革性研究。研究人员和学生将依次参加粗糙的STEM K-12外展计划，旨在开发能够解决明天问题的下一代科学家和工程师。膜是具有高效的油水分离的首选技术，例如能源效率，相对低材料成本及其拆除功能。膜以各种形式出现，这些形式由不同的聚合物或无机材料构建，并带有额外的部分，可控制膜表面的亲水性和/或授油。但是，一旦将膜的表面特性设置为渗透水，就无法更改它们以渗透到有时会堵塞毛孔的油中。设计一种将膜功能转换为往返石油或渗流的方法，将减轻结垢问题并能够收集油相。这种膜技术将使许多工业应用受益，包括使用低含水洪水的石油回收率或石油阶段有价值的乳制品行业增强。因此，研究人员提出了一种新的方法，以选择性地控制水和油流穿过膜原位。石油和水的润湿性将通过与吸附的表面分子相互作用来控制，这些表面分子与施加的电势更改会议。润湿性是控制液体流过孔隙的因素之一，以及几何和水解头。将仅在油水混合物中选择性地渗透到一个相的膜，如下所示：（1）首先，将确定在用电的水和油接触角（“控制分子”）中产生较大变化的表面分子。将计算和制造具有给定变化的最佳水压压力和几何形状。 （2）接下来，将制备一个带有带有水控制分子的最佳几何形状的膜。油也会为油做准备。膜的分离性能以及表面分子的耐用性将被表征。 （3）最终的项目目标是开发带有“控制阀”的膜，这些膜用两个控制分子涂有覆盖的膜，这些分子简单地调节了油和水的润湿性。将表征该杂交表面，并评估膜性能和耐用性。该项目的成功将使液态液分离的新方法能够增强进行研究的本科生和研究生的教育经验。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准通过评估来获得的支持。

项目成果

Active Control of Contact Angles of Various Liquids from the Response of Self-Assembled Thiol Molecules to Electric Current

• DOI: 10.1021/acs.langmuir.3c00026
• 发表时间: 2023-03
• 期刊: Langmuir
• 影响因子: 3.9
• 作者: D. Lippert;Jacob Burnham;Dongjin Seo