Temperature Dependence of Interfacial Bonding and Configuration Transition in Graphene/Hexagonal Boron Nitride Containing Grain Boundaries and Functional Groups

Abstract

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 sp2 to sp3. 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.

Mechanical Mechanism of Ion and Water Molecular Transport through Angstrom-Scale Graphene Derivatives Channels: From Atomic Model to Solid-Liquid Interaction

“…GO is rich in epoxy groups and hydroxyl groups on the lamellar plane, while the edges are mainly carbonyl groups and carboxyl groups [ 33 ]. At the same time, it can also be seen that a variety of oxygen-containing FGs (hydroxyl, epoxy, carbonyl, carboxyl and so on) are embedded on the surface and edge of the 2D lattice of graphene [ 34 , 35 ]. Therefore, a unique structure isolated from the sp 3 C-O matrix by numerous sp 2 -hybridized carbon atom clusters is generated.…”

Topological defects and nanoholes in graphene oxide/hexagonal boron nitride heterostructures: stress buildup and accumulation

“…GO is a non-stoichiometric material with layered structure, with hydroxyl (-OH) and epoxy groups (-O) on the surface and carboxyl (-COOH) on the edge. 18,19 These functional groups (FGOs) provide a large number of active sites for connecting various organic small molecules, polymers, biological macromolecules and other FGOs. 20,21 Due to the uneven distribution of oxygen-containing groups in GO, the sp 2 hybrid region is separated into "islands" with a size of 2-3 nm by the sp 3 hybrid C-O.…”