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

实验与模拟相结合，从分子层面理解膜污染机制

• 批准号: 1034158
• 负责人: Baoxia Mi
• 金额: --
• 依托单位: George Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2011-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1034158&HistoricalAwards=false
• 关键词: Integration; Experiments; Simulations; Molecular; Level

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.

摘要/ abstract摘要/ abstract项目名称：膜污染机理分子水平理解的实验与模拟集成本项目将整合分子模拟和多尺度实验表征，以实现对反渗透和纳滤（RO/NF）膜污染的分子水平理解。反渗透/纳滤膜越来越多地用于水分离和海水淡化。然而，长期存在的胶体/有机污染问题严重影响了反渗透/纳滤膜的性能。有效的污染缓解策略和高抗污染膜的发展依赖于对膜-污染物相互作用的基本理解。然而，目前试图了解膜特性对污染影响的实验研究往往得出不一致的结论。此外，目前开发防污材料的努力主要是基于实验试错，这是乏味的，昂贵的，耗时的。因此，我们迫切需要一种更有效的方法来设计新的防污材料。为了实现这一目标，他们将：(1)开发一种新的混合分子模拟方法，该方法特别适合模拟污染物与膜表面之间的长时间结合事件；(2)进行多尺度实验表征，包括原子力显微镜纳米尺度相互作用力测量、膜表面污物沉积的微观直接观察、膜长期污染行为的宏观表征；(3)将实验测量与分子模拟相结合，实现对膜污染的分子水平理解，从而极大地促进了新型防污膜的设计。该研究的新颖之处在于，它首次尝试将实验和分子模拟结合起来，系统地揭示分子水平的膜-污染物相互作用，这些相互作用仅通过实验或模拟方法都无法完全理解。该项目将为DLVO理论之外的许多膜-污染物相互作用提供敏锐的洞察力，如疏水/亲水性相互作用，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，以及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专门为膜污染研究设计的混合模拟工具箱。该项目将由两名具有实验膜表征和分子模拟专业知识的教师进行跨学科合作。因此，该项目有望揭示反渗透/纳滤膜工艺中污染现象的潜在机制，并促进防污膜材料的系统设计。对膜污染行为的分子水平理解将有助于开发下一代高耐污水分离膜。该研究对膜基水净化的能源效率和环境友好性具有重要影响，具有巨大的经济效益和社会效益。结合实验模拟方法将举例说明各种膜过程的基础研究范式，包括压力驱动过程（如超滤和微过滤）和渗透驱动过程（如正向渗透和延迟压力渗透），以及其他更广泛的领域（如废水回用，食品加工，生物能源生产）。两名博士研究生和几名本科生将积极参与拟议的项目。建议研究的材料和成果将整合到本科和研究生课程中。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）中代表性不足的学生。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。研究成果将通过期刊出版物、会议报告、研究网站和研讨会以及在校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项教育推广计划，并将提供有关可持续水净化和回收的环境技术的讲座。