CAREER: Atomic Scale Defect Engineering in Graphene Membranes

这项教师早期职业发展（Career）计划的目标是从实验和协作建模的角度来理解各种基本缺陷工程问题，包括悬浮石墨烯膜中单原子空位的气体传输测量，以及石墨烯膜中原子工程空位基于尺寸排除的气体分离演示。从炼油和水净化到二氧化碳捕获和封存以及天然气处理，分离过程对许多行业都至关重要。适用于高效分离屏障的膜应尽可能薄，以最大限度地提高通量，机械坚固，以防止破裂，并具有明确的孔径，以增加选择性。石墨烯是石墨的单原子层，代表了最薄的膜（一层原子）和最小的孔径（单原子空缺），以及前所未有的机械和化学稳定性。它代表了一种“理想的”分子筛，它可以通过排除较大的气体分子并允许较小的分子通过膜上原子大小的孔来分离气体混合物。为了实现石墨烯作为膜分离材料的非凡潜力，需要解决许多以前未被探索的科学问题，其中最重要的是在石墨烯中引入原子尺度的孔，这种孔可以基于尺寸排斥来分离气体。从对石墨烯膜缺陷工程的基本理解中获得的知识将为探索原子薄膜的节能分离能力开辟新的途径。这项工作的教育目标包括推广工作，以增加本科生和高中生参与机械工程课程的前沿研究项目和课程开发，特别是工程伦理和纳米技术。

The objective of this Faculty Early Career Development (CAREER) Program award is to understand a variety of fundamental defect engineering issues from an experimental and collaborative modeling perspective, including the measurement of gas transport across single atomic vacancies in suspended graphene membranes and the demonstration of gas separation based on size exclusion by atomically engineered vacancies in graphene membranes. Separation processes are critical to a large number of industries from oil refining and water purification to CO2 capture and sequestration and natural gas processing. Membranes suitable for energy efficient separation barriers should be as thin as possible to maximize flux, mechanically robust to prevent fracture, and have well-defined pore sizes to increase selectivity. Graphene, a single atomic layer of graphite, represents the thinnest membrane possible (one layer of atoms) with the smallest pore sizes attainable (single atomic vacancies), and unprecedented mechanical and chemical stability. It represents an "ideal" molecular sieve which can separate a mixture of gases by excluding larger gas molecules and allowing smaller molecules to pass through atomic size pores in the membrane.To realize the extraordinary potential of graphene as a material for membrane separations, a number of previously unexplored scientific issues need to be addressed, the most important being a means to introduce atomic scale pores in graphene which can separate gases based on size exclusion. The knowledge gained from a fundamental understanding of defect engineering in graphene membranes will open up new avenues to explore the energy efficient separation capabilities of atomically thin membranes. The educational objectives of the work include outreach efforts to increase the participation of undergraduate and high school students into cutting edge research projects and curriculum development in the Mechanical Engineering curriculum with a particular focus on engineering ethics and nanotechnology.