Engineered Applications of Carbon Nanotubes in Reverse Osmosis Membranes

PI：ChineumOsuji Proposal编号：1133484水量和水质的下降加速了海水淡化作为可靠的饮用水来源的采用。然而，基于膜的海水淡化技术的广泛实施受到高能源需求的限制。需要对反渗透(RO)膜进行根本性的重新设计，以满足能源受限环境中的水资源需求。这项研究的主要目标是通过增加膜的渗透性和减少污染来减少膜法海水淡化的能源需求。该项目利用碳纳米管(CNTs)的独特性能来设计高通量和抗生物污染的新型反渗透膜。第一个目标是通过将单壁碳纳米管(SWNTs)引入薄膜屏障来提高传统薄膜复合(TFC)反渗透膜的渗透性并减少生物污染。他们假设，单壁碳纳米管将扰乱聚酰胺薄膜的聚合物填充结构，从而增强传统TFC膜的渗透性。单壁碳纳米管的抗菌特性也为膜生物污染的防治提供了新的策略。这项研究将优化SWNT在TFC反渗透膜中的掺入，评估SWNTs对膜的通透性和选择性的影响，量化SWNT-TFC膜表面的微生物灭活，并阐明提高通透性和细菌细胞毒性的机制。这项研究的第二个目标是制备定向的单壁碳纳米管薄膜。理论预测通过定向碳纳米管膜具有高通量和高盐截留率，但目前的制备技术不能通过尺寸排斥机制生产满足理论要求的脱盐膜。使用液晶试剂合成后排列的单壁碳纳米管将得到直径小到足以拒绝水合盐离子的单壁碳纳米管薄膜。他们的研究将涉及单壁碳纳米管的制备和表征、液晶体系的优化和表征、单壁碳纳米管的取向演示、定向单壁碳纳米管膜的表征以及膜的孔隙率的优化。所提出的研究将为制备具有高渗透性和低生物污染倾向的坚固的反渗透膜奠定科学基础。这些新一代反渗透膜将大大减少海水淡化的能源使用和成本，从而为通过海水淡化增加全球水供应并使其多样化提供一条可行的途径。从这项研究中获得的知识可以很容易地用于开发高选择性的碳纳米管超滤和纳滤膜，可用于生物医学、化学、分析和环境分离过程。所需资金的大部分将用于培养一名博士生，从事一项新兴的跨学科研究课题。学生将有机会担任新开发的聚合物物理课程的助教，该课程以实验技术实验模块为特色，在拟议的工作中大量使用。另外，两名本科生将作为这个项目的一部分进行他们的高级论文研究。国际和平协会和联合国际都致力于招募科学界代表性不足的群体，并将在这个项目中推动这一目标。拟议的工作将作为设计和实施高中科学项目的基础，作为纽黑文学生科学博览会和科学教师研究经验(RESCT)计划的一部分。至关重要的是，这些外展工作促进了K-12科学教育，并提高了人们对水质和环境问题的认识。除了研究和教育方面的好处，拟议的工作还有可能产生深远的、切实的社会影响，因为它直接涉及科学进步和技术发展，以解决一个紧迫的问题。

PI: Chinedum OsujiProposal Number: 1133484Decline in water quantity and quality has accelerated the adoption of desalination as a reliable source of potable water. Widespread implementation of membrane-based desalination technologies, however, is constrained by the high energy requirement. A fundamental redesign of reverse osmosis (RO) membranes will be needed to meet water resource needs in an energy constrained environment. The overarching aim of the proposed research is to reduce the energy demands of membrane-based desalination by increasing membrane permeability and reducing fouling. This project exploits the unique properties of carbon nanotubes (CNTs) in the design of novel RO membranes with high flux and resistance to biofouling. The first objective is to improve permeability and reduce biofouling of conventional thin-film composite (TFC) RO membranes by incorporating single-walled carbon nanotubes (SWNTs) into the thin-film barrier. They hypothesize that SWNTs will perturb the polymer packing structure of the thin-film polyamide layer, thereby enhancing the permeability of conventional TFC membranes. The antimicrobial characteristics of SWNTs also offer novel strategies for the prevention of membrane biofouling. The proposed research will optimize SWNT incorporation into TFC RO membranes, evaluate the impact of SWNTs on membrane permeability and selectivity, quantify microbial inactivation at the SWNT-TFC membrane surface, and elucidate the mechanistic pathways for permeability enhancement and bacterial cytotoxicity. The second objective of the proposed research is to fabricate an aligned SWNT membrane. Theory predicts high flux and high salt rejection through aligned CNT membranes, but current fabrication techniques cannot produce membranes that meet theoretical requirements for desalination through a size exclusion mechanism. Post-synthesis alignment of SWNTs using liquid crystalline agents will yield a membrane with SWNT diameters small enough to reject hydrated salt ions. Their research will involve the preparation and characterization of SWNTs, optimization and characterization of the liquid crystalline system, demonstration of SWNT alignment, characterization of aligned SWNT membranes, and optimization of membrane porosity.The proposed research will develop the scientific base for the fabrication of robust RO membranes with high permeability and reduced biofouling propensity. These next generation RO membranes will substantially reduce the energy use and cost of desalination, thereby providing a viable avenue for augmenting and diversifying global water supplies via seawater desalination. Knowledge gained from this research can be readily applied to the development of highly selective carbon nanotube-based ultrafiltration and nanofiltration membranes that can be used in biomedical, chemical, analytical, and environmental separation processes.The majority of requested funds will be applied toward the training of a doctoral student on an emerging and interdisciplinary research topic. The student will have the opportunity to serve as a TA on a newly developed Polymer Physics course that features a lab module on experimental techniques heavily utilized in the proposed work. Additionally, two undergraduate students will carry out their senior theses research as part of this project. Both the PI and co-PI are committed to recruitment of underrepresented groups in science and will further that goal in this project. The proposed work will be used as the basis for the design and implementation of high school science projects, as part of the New Haven Science Fair for students and a Research Experience for Science Teachers (REScT) program. Critically, these outreach efforts advance K-12 science education and increase awareness of water quality and environmental issues. Beyond the research and educational benefits, the proposed work has the potential for profound, tangible societal impact, as it directly addresses the advancement of science and development of technology to tackle a pressing concern.