Topological Design of Tough Multi-functional 2D Materials

该奖项支持开发通过拓扑设计来定制二维(2D)材料的机械和物理属性的方法。2D材料是由单层原子组成的晶体材料。这些材料有各种各样的化学成分、晶体相和物理形式，预计将在电子、传感器、涂层、屏障、能量存储和转换、水净化和生物医学等领域实现大量未来技术。虽然这些有前景的应用中的每一个都强调了2D材料的不同方面，但它们都要求材料的结构可靠性和抗故障能力。最近，人们已经清楚地看到，虽然2D材料可以获得超高的强度和近乎完美的原子结构，但它们通常非常脆弱，不易断裂。这是一个重要的问题，因为大规模的制造将不可避免地在2D材料中引入裂缝。2D材料的本质脆性、不可避免的裂纹和腐蚀环境使得断裂成为2D材料工业应用中最突出的问题之一。这项研究的结果将使美国经济和社会受益，因为2D材料的全球市场预计在未来几十年将接近数十亿美元。这项研究的多学科方法将对布朗大学的工程教育和推广活动产生积极的影响。研究将解决以下两个问题：通过拓扑设计可以在多大程度上提高2D材料的韧性？拓扑增韧的2D材料有望达到什么样的热-机-电性能？所研究的问题将通过基于相场晶体方法、原子模拟、密度泛函计算和连续介质理论的多尺度方法来解决。技术方法将以PI开发的经验和理论/模拟能力为基础。这项工作将包括开发一种用于2D材料拓扑设计的通用方法，并通过原子模拟、DFT计算和连续介质建模/模拟来研究所设计结构的机械性能，如拉伸、弯曲、起皱、撕裂、断裂、渗透以及热和电性能。将开发具有目标性质的设计相图，以启发实验合成。这项工作中的超大规模模拟将在国家计算科学研究所进行，其余的计算工作将在布朗大学的计算和可视化中心进行。

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.