Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072, China.
Int J Mol Sci. 2022 Jan 27;23(3):1433. doi: 10.3390/ijms23031433.
The quasi-three-dimensional effect induced by functional groups (FGo) and the in-plane stress and structural deformation induced by grain boundaries (GBs) may produce more novel physical effects. These physical effects are particularly significant in high-temperature environments and are different from the behavior in bulk materials, so its physical mechanism is worth exploring. Considering the external field (strain and temperature field), the internal field (FGo and GBs) and the effect of distance between FGs and GBs on the bonding energy, configuration transition, and stress distribution of graphene/h-BN with FGo and GBs (GrO-BN-GBs) in the interface region were studied by molecular dynamics (MD). The results show that the regions linked by hydroxyl + epoxy groups gradually change from honeycomb to diamond-like structures as a result of a hybridization transition from sp to sp. The built-in distortion stress field generated by the coupling effect of temperature and tension loading induces the local geometric buckling of two-dimensional materials, according the von Mises stresses and deflection theory. In addition, the internal (FGo and GBs) and external field (strain and temperature field) have a negative chain reaction on the mechanical properties of GrO-BN-GBs, and the negative chain reaction increases gradually with the increase in the distance between FGo and GBs. These physical effects are particularly obvious in high-temperature environments, and the behavior of physical effects in two-dimensional materials is different from that in bulk materials, so its physical mechanism is worth exploring.
功能基团(FGo)引起的准三维效应和晶界(GBs)引起的面内应力和结构变形可能会产生更多新颖的物理效应。这些物理效应在高温环境下尤为显著,与体材料中的行为不同,因此其物理机制值得探索。考虑到外场(应变和温度场)、内场(FGo 和 GBs)以及 FGs 和 GBs 之间距离对具有 FGo 和 GBs 的石墨烯/六方氮化硼(GrO-BN-GBs)在界面区域的结合能、构型转变和应力分布的影响,采用分子动力学(MD)对其进行了研究。结果表明,由于 sp 到 sp 的杂化转变,由羟基+环氧基团连接的区域逐渐从蜂窝状转变为类金刚石结构。根据 von Mises 应力和挠度理论,温度和拉伸加载的耦合效应产生的内置畸变应力场导致二维材料的局部几何屈曲。此外,内部(FGo 和 GBs)和外部场(应变和温度场)对 GrO-BN-GBs 的力学性能具有负连锁反应,随着 FGo 和 GBs 之间距离的增加,负连锁反应逐渐增加。这些物理效应在高温环境下尤为明显,二维材料中物理效应的行为与体材料中的行为不同,因此其物理机制值得探索。