Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Nanotechnology. 2010 Jan 29;21(4):045704. doi: 10.1088/0957-4484/21/4/045704. Epub 2009 Dec 16.
Graphene epoxide, with oxygen atoms lining up on pristine graphene sheets, is investigated theoretically here using first-principles calculations. Two distinct phases-metastable clamped and stable unzipped structures-are observed consistent with experimental observations. In the clamped structure, oxygen atoms form a regular lattice on the graphene sheet. In the unzipped phase, an epoxy group breaks the lower sp(2) bond and modifies the mechanical and electronic properties of graphene remarkably. The foldable epoxy ring structure reduces its Young's modulus by 42.4%, while leaving the tensile strength almost unchanged. The perturbation of epoxidation on the band structures depends on the density and symmetry of oxidation. These results pave the way for oxidation-based engineering of graphene-related materials.
本文通过第一性原理计算，对沿原始石墨烯片排列的氧原子的氧化石墨烯进行了理论研究。实验观察到两种不同的相——亚稳夹合结构和稳定的开环结构。在夹合结构中，氧原子在石墨烯片上形成规则的晶格。在开环相中，环氧基打断了较低的 sp(2)键，并显著改变了石墨烯的力学和电子性质。可折叠的环氧环结构使其杨氏模量降低了 42.4%，而拉伸强度几乎保持不变。氧化对能带结构的影响取决于氧化的密度和对称性。这些结果为基于氧化的石墨烯相关材料的工程设计铺平了道路。
