CAREER: A Few Layer Thin, Graphene-Based Membranes: Nanostructure Understanding, Permeation Mechanisms and Separation Applications

1451887 Yu哥伦比亚大学卡罗莱纳这项研究的目标是合理设计几层薄（厚度3 nm）的石墨烯基膜，了解它们的纳米结构和渗透机制，并研究它们对各种混合物的选择性高通量分离的潜力。 这项拟议的研究预计将有很大的科学和技术的影响，混合物分离，并有很大的潜力，革命性的分离使用膜技术。如果成功，这种具有可调材料性质、膜纳米结构和结构缺陷尺寸的新一代膜将在高通量混合物分离中具有广泛的应用，包括气体分离、液体混合物分离和纳滤等。从而大大降低了分离中的能源成本。预计该研究可以作为具有可调膜性能的石墨烯基膜的合理设计的模型。此外，对石墨烯基涂层沉积和涂层纳米结构的基本理解和知识可能会对光电子应用产生潜在影响，例如触摸屏和有机发光二极管（OLED），能量存储和光伏电池。 具有合理设计和优化的纳米结构的超薄膜具有实现高通量有效混合物分离的巨大潜力。拟议的研究将集中在制造，纳米结构澄清，和分离研究的几层薄，石墨烯为基础的膜。提出的研究的目标是i）应用液相沉积工艺可控地存款几层薄的石墨烯基膜; ii）阐明所制造的膜的纳米结构并将沉积参数与所得纳米结构相关联; iii）理解分子通过几层薄膜的渗透机制并研究控制孔径的各种蚀刻工艺;和iv）探索几层薄的石墨烯基膜对各种气体和液体混合物的分离潜力。我们将通过真空过滤、浸涂和浇铸蒸发在适当的多孔基底上沉积具有可控性质的存款氧化石墨烯（GO）薄片;采用宏观和微观技术来表征沉积的薄涂层/膜的纳米结构;通过气体、蒸汽和液体渗透来探索通过GO和还原GO（rGO）的分子传输路径，包括层间距和结构缺陷;研究了加压气体渗透、渗透蒸发和液体过滤分离混合物的方法。PI建议通过促进所有学生在STEM领域的教育来整合研究和教育，特别强调提高少数民族学生在这一人口中的保留率。PI利用南加州大学的一些现有项目来提供组织结构并为各种活动提供资源。具体而言，PI计划（1）在研究领域开发一个专题研究生班，（2）尝试招募一名GEM学者作为博士生导师，（3）每年接待2名URM本科研究人员，（4）参加南加州大学组织的K-12外联活动，并与一所少数民族高中建立持续的关系，其中包括PI每年4次访问。

1451887YuUniversity of Sourth Carolina at ColumbiaThe goal of this proposed research is to rationally design few layer thin (thickness 3 nm), graphene-based membranes, understand their nanostructures and permeation mechanisms, and study their potential for selective, high flux separation of a wide range of mixtures. This proposed research is expected to have great scientific as well as technological impact on mixture separations and has great potential to revolutionize separation using membrane technology. If successful, this new generation ultrathin membranes with tunable material properties, membrane nanostructures, and structural defects sizes will have wide applications for high throughput mixture separations, including gas separation, liquid mixture separation, and nanofiltration, etc., and thus greatly reduce energy cost in separations. It is anticipated that this study could serve as a model for the rational design of ultrathin, graphene-based membranes with tunable membrane performance. In addition, the obtained fundamental understanding and knowledge on graphene-based coating deposition and coating nanostructures may have potential impact on optoelectronics applications, such as touch screens and organic light emitting diodes (OLEDs), energy storage, and photovoltaic cells. Ultrathin membranes with rationally designed and optimized nanostructures have great potential to achieve effective mixture separation with high throughput. The proposed research will focus on fabrication, nanostructure clarification, and separation study of a few layer thin, graphene-based membranes. The objectives of the proposed research are i) applying liquid phase deposition processes to controllably deposit a few layer thin, graphene-based membranes; ii) elucidating the nanostructures of fabricated membranes and correlating the deposition parameters with the resulting nanostructures; iii) understanding permeation mechanisms of molecules through the a few layer thin membranes and investigating various etching processes on controlling pore sizes; and iv) exploring the separation potential of a few layer thin, graphene-based membranes for various gas and liquid mixtures. We will deposit graphene oxide (GO) flakes with controlled properties on appropriate porous substrates by vacuum filtration, dip-coating, and casting-evaporation; employ both macroscopic and microscopic techniques to characterize the nanostructures of deposited thin coatings/membranes; explore molecular transport pathways through GO and reduced GO (rGO), including interlayer spacing and structural defects, by gas, vapor and liquid permeation; study the separation of mixtures by pressurized gas permeation, pervaporation and liquid filtration. The PI proposes the integration of research and education through advancement of the education of all students in the STEM fields with special emphasis on enhancing retention of minority students in this population. The PI has leveraged a number of existing programs at USC to provide organizational structure and to resource the various activities. Specifically, the PI plans(1) the development of a special topics graduate class in the study area, (2) try to recruit a GEM scholar as a PhD mentee, (3) host 2 URM undergraduate researchers per year, (4) participate in K-12 outreach organized by USC and develop a continuous relationship with one minority serving high school that will include 4 visits from the PI each year.