Editor's note: Under unconstrained or weakly constrained conditions, graphene will inevitably buckle under thermal disturbance. This process is controlled by two key physical quantities-normal bending stiffness and Gaussian bending stiffness. Wei Yujie, the State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, found that the bending rigidity of single-layer graphene is close to that of biological cell membranes, which indicates mechanically that this material and biological cells may easily match each other.
Recently, a paper on the bending stiffness and Gaussian bending characteristics of single-layer graphene was published in the journal NanoLetters by Wei Yujie, a researcher at the State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences.
Under unconstrained or weakly constrained conditions, graphene will inevitably buckle under thermal disturbance. This process is controlled by two key physical quantities-normal bending stiffness and Gaussian bending stiffness. According to the geometric characteristics of fullerenes and single-walled carbon nanotubes, two main radii of curvature are needed to determine the geometry of fullerenes, but carbon tubes only need one radius of curvature.
This feature allows researchers to combine first-principle calculations with Helfrich Hamiltonian to accurately determine the bending stiffness and Gaussian bending coefficient of single-layer graphene. The results show that the normal bending stiffness of single-layer graphene is 1.44 eV (2.31 × 10-19 Nm), while its Gaussian bending stiffness is -1.52 eV (2.43 × 10-19 Nm). Wei Yujie and others found that the bending stiffness of single-layer graphene is close to that of biological cell membranes, which indicates mechanically that the material and biological cells may easily match each other.
Figure 1: Schematic diagram showing the two key spring constants controlling the buckling of a single layer of graphene. According to the geometric characteristics of fullerene and single-walled carbon nanotubes, we need two main radii of curvature to determine the geometry of fullerenes, but carbon tubes only need one radius of curvature. This feature allows us to combine the first-principle calculation with the Helfrich Hamiltonian to determine the bending stiffness and Gaussian bending coefficient of single-layer graphene.
Food Grade Essential Oil,Cumin Oil,Garlic Oil,Black Pepper Oil
Ji'An ZhongXiang Natural Plants Co.,Ltd. , https://www.jxzxessentialoils.com