This award supports the development of methods to tailor the mechanical and physical properties of two-dimensional (2D) materials through topological design. 2D materials are crystalline materials consisting of a single layer of atoms. These materials come in a wide array of chemical compositions, crystal phases, and physical forms, and are anticipated to enable a host of future technologies in areas that include electronics, sensors, coatings, barriers, energy storage and conversion, water purification and biomedicine. While each of these promising applications emphasizes a different aspect of 2D materials, they all require structural reliability and resistance to failure of the materials. Recently, it has become clear that, while 2D materials can achieve ultra-high strength with nearly perfect atomic structures, they are typically very fragile against fracture. This is an important concern as large scale fabrication will inevitably introduce cracks in 2D materials. The intrinsically brittle nature, inevitable cracks and corrosive environment make fracture one of the most prominent concerns in industrial applications of 2D materials. Results from this research will benefit the U.S. economy and society, as the global market for 2D materials is expected to approach billions of dollars in the coming decades. The multi-disciplinary approach of the research will positively impact engineering education and outreach activities at Brown University.
The research will address the following two questions: To what extent can the toughness of 2D materials be enhanced through topological design? What thermal-mechanical-electrical properties could the topologically toughened 2D materials hope to achieve? The problems under study will be tackled via a multi-scale approach based on phase field crystal method, atomistic simulations, DFT calculations and continuum theories. The technical approach will be based on the experience and theoretical/simulation capabilities developed by the PI. The work will include the development of a general methodology for topological design of 2D materials and investigation of mechanical properties such as stretching, bending, wrinkling, tearing, fracture, penetration, as well as thermal and electrical properties of designed structures via atomistic simulation, DFT calculation, and continuum modeling/simulations. Design phase diagrams with targeted properties will be developed to inspire experimental synthesis. The ultra-large scale simulations in the work will be performed on the National Institute for Computational Sciences, and the rest of the computational work will be performed at the Center for Computing and Visualization at Brown University.
