CBET-EPSRC A Game-Changing Approach for Tunable Membrane Development: Novel Covalent Organic Framework Active Layers Supported by Solvent Resistant Materials

CBET-EPSRC 可调膜开发的改变游戏规则的方法：由耐溶剂材料支持的新型共价有机框架活性层

基本信息

批准号：
1706219
负责人：
Benito Marinas
金额：
$ 45万
依托单位：
University of Illinois at Urbana-Champaign
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-01 至 2021-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1706219&HistoricalAwards=false
关键词：
CBET EPSRC Game Changing Approach

项目摘要

Title: CBET-EPSRC A Game-Changing Approach for Tunable Membrane Development: Novel Covalent Organic Framework Active Layers Supported by Solvent Resistant Materials 1706219 Marinas Surface and groundwater may be purified to drinking water quality standards via nanofiltration, a pressure-driven process which relies on a membrane as a physical barrier to remove contaminants from water. The membrane allows water to pass through its nanometer size pores at a higher rate compared to dissolved and/or suspended solutes, resulting in purification of the water that passes through the membrane. To achieve even higher water quality, more selective reverse osmosis membranes have sub-nanometer pores, which require higher applied pressure to facilitate water transport across the membrane. There is a general trade-off between permeability of the membrane to water versus impermeability to contaminants: smaller pore sizes retain a broader range of contaminants but decrease water throughput per unit time and/or increases energy consumption; in contrast, larger pore sizes lead to less contaminant rejection but higher water permeability or lower energy consumption. State of the art membranes are made from polymers, for which the spaces between the polymeric chains act as the pores that filter the contaminants. As these pores are formed via the three-dimensional arrangement of polymer chains, the pore size is not easily controlled on a molecular level. Current membranes have a limited lifetime, due to the negative effects of biofouling, mechanical compaction, and chemical degradation. Biofouling is a result of the deposition of organic contaminants and nutrients on the membrane and the subsequent growth of a biofilm that creates a barrier for subsequent water permeation through the membrane; polymer compaction results in pore tightening in the amorphous portion of membranes that leads to reduced water permeability; and chemical degradation is a process exacerbated by the use of harsh chemicals during cleaning of fouled membranes that ultimately results in higher permeability to contaminants. To address these concerns, this project will develop novel membranes that enable a molecular-level design of pore size and shape and the incorporation of fouling-resistant chemical functional groups. The project capitalizes upon a new interfacial polymerization process that synthesizes covalent organic frameworks in a high-surface area thin polymeric film. Unlike other polymeric materials, these frameworks are highly crystalline with well-defined surface chemistry and a regular pore structure, this regularity enables molecular level design, which in turn will allow for optimized retention of particular solutes combined with high water permeability across the membrane. The frameworks could also be modified to incorporate anti-fouling surface chemistry and to decrease pore size. The key advance of this collaborative project is to develop the thin active covalent organic framework layer in concert with a polymeric support that is stable in the solvents used for the polymerization process and during membrane cleaning. The project scope of work includes synthesis of novel membranes with various building blocks, tuning of pore size and surface chemistry by altering the covalent organic framework, and the identification of solvent stable support media. Various surface analysis techniques will be used for the physicochemical characterization of the resulting membranes, and optimization of the interfacial polymerization process to control the interface between the covalent organic framework and the support. The resulting membranes will be tested for performance with aqueous solutions of model contaminants. This international collaboration, facilitated by an inter-agency agreement between the U.S. and U.K., brings together membrane and polymer synthesis experts from two countries to develop this new class of membranes while building an international research network and providing students with a unique international educational opportunity.

标题：CBET-EPSRC一种可调膜开发的改变游戏的方法：新型共价有机框架主动层由溶剂抗性材料支撑1706219 Marinas表面和地下水可以通过纳米滤过为饮用水质量标准，这是一种压力驱动的过程，该工艺可将其偏向于膜的含量，以使膜的偏移偏移，以使杂物脱落。与溶解和/或悬浮的溶质相比，该膜使水通过其纳米尺寸孔隙较高，从而导致通过膜的水纯化。为了达到更高的水质，更具选择性的反渗透膜具有亚纳米孔，需要更高的施加压力以促进整个膜的水运输。膜上水与污染物的不渗透性之间的渗透性之间存在普遍的权衡：较小的孔径保留了更广泛的污染物，但每单位时间降低水吞吐量和/或增加能源消耗；相比之下，较大的孔径会导致污染物排斥不足，但渗透性较高或能源消耗较低。最先进的膜是由聚合物制成的，聚合物链之间的空间充当过滤污染物的孔。由于这些孔通过聚合物链的三维排列形成，因此孔径不容易在分子水平上控制。由于生物污染，机械压实和化学降解的负面影响，当前的膜的寿命有限。生物污染是膜上有机污染物和养分沉积的结果，以及随后的生物膜的生长，从而产生了随后通过膜渗透的障碍。聚合物压实会导致膜的无定形部分的孔隙拧紧，从而导致水渗透性降低。化学降解是在清洁污染膜期间使用苛刻的化学物质加剧的过程，最终导致对污染物的渗透性更高。为了解决这些问题，该项目将开发出新的膜，该膜能够实现孔径和形状的分子级设计，并掺入耐药化学官能团。该项目利用了新的界面聚合过程，该过程综合了高表面区域薄聚合物膜中共价有机框架。与其他聚合材料不同，这些框架是高度结晶的，具有明确的表面化学和规则的孔结构，这种规律性可以使分子水平的设计，进而可以优化对特定溶质的保留，并在整个膜上加水。该框架也可以修改以结合抗污染的表面化学和减小孔径。这个协作项目的主要进步是与聚合物支撑一起开发薄的活跃共价有机框架层，该层在聚合过程中和膜清洁过程中使用的溶剂稳定。工作范围包括通过改变共价有机框架来合成具有各种构件的新型膜，对孔径和表面化学的调整以及鉴定溶剂稳定的支撑介质。各种表面分析技术将用于所得膜的理化表征，并优化界面聚合过程，以控制共价有机框架与支撑之间的界面。所得的膜将通过模型污染物的水溶液进行测试。这项国际合作是由美国与英国之间的一项机构间协议促进的，汇集了来自两个国家的膜和聚合物合成专家，以开发这一新的膜，同时建立国际研究网络，并为学生提供独特的国际教育机会。