Integration of Experiments and Simulations for Molecular-Level Understanding of Membrane Fouling Mechanisms

摘要PI：表侠建议书编号：CBET-1034158机构：乔治华盛顿大学标题：整合实验和模拟的膜污染机理的分子水平的理解这个项目将整合分子模拟和多尺度实验表征，以实现反渗透和纳滤（RO/NF）膜污染的分子水平的理解。 RO/NF膜越来越多地用于水分离和脱盐。 然而，RO/NF膜的性能受到长期存在的胶体/有机污染问题的严重阻碍。 开发有效的污垢缓解策略和高foulingresistant膜依赖于膜污垢相互作用的基本理解。 然而，目前的实验研究试图了解膜性能对污染的影响往往得出不一致的结论。 此外，目前开发纳米材料的努力大多基于实验试错，这是繁琐、昂贵和耗时的。 因此，我们迫切需要一种更有效的方法来设计新的纳米材料。 为了实现这一目标，他们将：（1）开发一种新型的混合分子模拟方法，特别适合模拟污垢和膜表面之间的长期结合事件;（2）进行多尺度实验表征，包括通过原子力显微镜测量纳米级相互作用力，显微镜直接观察膜表面上的污垢沉积，和长期膜污染行为的宏观表征;以及（3）整合实验测量和分子模拟以实现对膜污染的分子水平的理解，从而极大地促进了新型疏水膜的设计。所提出的研究的新奇在于，它代表了第一个-以往任何时候都试图整合实验和分子模拟的努力，系统地揭示分子水平的膜污垢的相互作用，这不能完全理解的实验或模拟方法单独。 该项目将提供对DLVO理论之外的许多膜污垢相互作用的敏锐洞察，例如疏水/亲水相互作用，形态/化学异质性依赖的相互作用，官能团控制的特异性相互作用和柔性链诱导的相互作用。 这项研究的一个主要成果将是一个混合模拟工具箱，是专门为膜污染研究设计的。 该项目将通过两名教师之间的跨学科合作进行，他们在实验膜表征和分子模拟方面具有共同的专业知识。 因此，本研究将有助于揭示反渗透/纳滤膜过程中膜污染现象的机理，促进反渗透膜材料的系统设计，从分子水平了解膜污染行为，有助于开发新一代高抗污染的水分离膜。 该研究还对膜基水净化的能源效率和环境友好性方面产生了重大影响，带来了巨大的经济和社会效益。 实验-模拟相结合的方法将成为各种膜过程基础研究的范例，包括压力驱动过程（如超滤和微滤）和渗透驱动过程（如正向渗透和压力延迟渗透），以及其他更广泛的领域（例如，废水再利用、食品加工、生物能源生产）。 两名博士研究生将接受培训，几名本科生将积极参与拟议的项目。 材料和拟议的研究成果将被整合到本科和研究生课程。 拟议的研究活动还将影响现有大学联盟内邻近机构（包括两所历史上的黑人大学）代表性不足的学生。 PI和co-PI之间的密切合作将激发批判性思维和创造性想法。 研究结果将通过期刊出版物，会议演示，研究网站和研讨会，以及在校园工程开放日期间向公众传播。 PI在当地一所女子高中发起了一个教育推广方案，并将提供关于可持续水净化和回收的环境技术的讲座。

AbstractPI: Biaoxia MiProposal Number: CBET-1034158Institution: George Washington UniversityTitle: Integration of Experiments and Simulations for Molecular-Level Understanding of Membrane Fouling MechanismsThis project will integrate molecular simulation and multiscale experimental characterization to achieve a molecular-level understanding of the fouling of reverse osmosis and nanofiltration (RO/NF) membranes. RO/NF membranes are increasingly being used for water separation and desalination. However, the performance of RO/NF membranes is severely hampered by the long-standing problem of colloidal/organic fouling. Development of efficient fouling-mitigation strategies and highly foulingresistant membranes relies on the fundamental understanding of membrane-foulant interactions. However, current experimental studies attempting to understand the effects of membrane properties on fouling often draw inconsistent conclusions. In addition, current efforts to develop antifouling materials are mostly based on experimental trial-and-error, which is tedious, expensive, and time-consuming. Therefore, we urgently need a more efficient approach to designing new antifouling materials. Towards this goal, they will: (1) develop a novel hybrid molecular simulation approach that is specifically fit for simulating the long-time binding events between foulants and membrane surfaces; (2) conduct multiscale experimental characterization, including nanoscale interaction force measurement by atomic force microscopy, microscopic direct-observation of foulant-deposition on membrane surfaces, and macroscopic characterization of long-term membrane fouling behavior; and (3) integrate experimental measurements and molecular simulations to achieve a molecular-level understanding of membrane fouling, thus greatly facilitating the design of novel antifouling membranes.The novelty of the proposed study is that it represents the first-ever attempt to integrate experimental and molecular simulation efforts to systematically unveil the molecular-level membrane-foulant interactions, which cannot be fully understood by either experimental or simulation approaches alone. This project will offer keen insight into many membrane-foulant interactions beyond the DLVO theory, such as hydrophobic/hydrophilic interactions, morphological/chemical heterogeneity dependent interactions, functional-group-controlled specific interactions, and flexible-chain induced interactions. A major outcome of this research will be a hybrid simulation toolbox that is specifically designed for membrane fouling studies. This project will be conducted through an interdisciplinary collaboration between two faculty members with a joint expertise in experimental membrane characterization and molecular simulations. Thus, it is highly promising that the proposed project will unveil the underlying mechanisms of fouling phenomena in RO/NF membrane processes and facilitate systematic design of antifouling membrane materials.Molecular-level understanding of the membrane fouling behavior will help develop the next-generation highly fouling-resistant membranes for water separation. The research also has significant impacts on energy efficiency and environmental friendliness aspects of membrane-based water purification, leading to huge economic and societal benefits. The combined experimental-simulation approach will exemplify a paradigm of fundamental study on various membrane processes, including pressure-driven processes (such as ultrafiltration and microfiltration) and osmotically driven processes (such as forward osmosis and pressure-retarded osmosis), as well as in other broader areas (e.g., wastewater reuse, food processing, bioenergy production). Two PhD graduate students will be trained and several undergraduate students will be actively involved in the proposed project. Materials and outcomes of the proposed research will be integrated into both undergraduate and graduate courses. The proposed research activities will also impact underrepresented students at neighboring institutions (including two historically black universities) within an existing university consortium. The close collaborations between the PI and co-PI will stimulate critical thinking and creative ideas. Research findings will be disseminated through journal publications, conference presentations, research websites, and seminars, as well as to the general public during the on-campus Engineering Open House. The PI has initiated an educational outreach program at a local girls-only high school and will offer lectures on the environmental technologies for sustainable water purification and reclamation.