CAREER: Atomic Scale Defect Engineering in Graphene Membranes

这个教师早期职业发展（CAREER）计划奖的目的是从实验和协作建模的角度了解各种基本的缺陷工程问题，包括测量悬浮石墨烯膜中单个原子空位的气体传输，以及基于石墨烯膜中原子工程空位的尺寸排阻的气体分离演示。分离过程对于从炼油和水净化到CO2捕获和封存以及天然气加工的许多行业至关重要。适用于节能分离屏障的膜应尽可能薄以最大化通量，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，代表了可能的最薄的膜（一层原子），具有可达到的最小孔径（单原子空位）和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，可以通过排除较大的气体分子并允许较小的分子通过膜中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，需要解决一些以前未探索的科学问题，最重要的是在石墨烯中引入原子级孔的手段，其可以基于尺寸排阻分离气体。从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级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外展工作，以增加本科生和高中生参与尖端研究项目和机械工程课程的课程开发，特别注重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.