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

基本信息

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

项目摘要

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.

该项目的目标是使用特殊的膜（具有非常小的孔/通道的过滤器）分离油和水，该膜通过施加电势来改变每种流体在膜表面的行为。油水分离的效率取决于例如，亲水性或亲水性的膜允许水通过，但会排斥油，但是油最终会堵塞孔，从而阻止额外的水通过膜。得到解决，如果当油相很有价值时，例如在油水混合物丰富的原油生产中，或者在油相中，这种可切换的功能将特别有用。不幸的是，在乳制品行业，油相和水相都很有价值，在操作过程中改变膜特性的能力很难实现，该项目将通过用改变膜方向的分子来改变膜的表面特性来实现这一目标。首先，分子对电做出反应并产生结果。作为该项目的中间目标，将通过在膜表面涂覆水控制分子来开发能够控制水流的膜。最终，通过涂覆控油分子和控水分子，可以控制油和水的流动，从而根据需要分离油水混合物。在废水处理中，此外，该项目将直接让本科生和研究生参与有影响力的变革性研究，而研究人员和学生将参与农村 STEM K-12 推广项目。考虑到能源效率、相对较低的材料成本及其破乳功能等因素，膜是高效油水分离的首选技术。由不同聚合物构成的形式然而，一旦膜的表面特性被设定为渗透水，它们就不能被改变以渗透最终堵塞孔的油。将膜功能切换为油渗透或水渗透将减轻污染问题并能够收集油相，这种膜技术将有利于许多工业应用，包括通过低盐度水驱提高石油采收率。因此，研究人员提出了一种新方法，可以通过与吸附的表面分子相互作用来控制油和水的润湿性，从而改变其构象。施加的电势是控制液体流过孔隙的因素之一，同时膜的几何形状和水头可以选择性地从油水混合物中渗透，如下：(1)首先，将确定水和油与电的接触角发生较大变化的表面分子（“控制分子”），并计算和制作给定变化的最佳水压和几何形状。将制备一种具有最佳几何形状的、涂有控水分子的膜，该膜将用于表征膜的分离性能以及表面分子的耐久性。就是开发一种带有“控制阀”的膜涂有两种同时调节油和水润湿性的控制分子的膜将被表征，并且该项目的成功将实现液液分离的新方法并增强教育意义。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。