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.
