Thermal stability of a nanoporous graphene membrane candidate from an orthogonal-diagonal nanotexture: A molecular dynamics test

Abstract

Graphene-based membranes are popular for ionic and molecular sieving. For keeping the permeability and selectivity, both the membrane structure and the pores should be stable in the filtration process. In this study, a new model of membrane candidate was proposed upon orthogonal-diagonal graphene ribbon-knitted nanotexture. A brief weaving process was introduced. Using molecular dynamics simulations, we evaluated thermal stability of the nanoporous graphene nanotextures by characterizing their shapes and the nanometer-sized periodic pores. Results demonstrate that the most of the present nanotextures have stable structures. Compared to the orthogonal graphene nanotextures in Ref. Yang et al. [1], the stronger structural stability of the present nanotextures are due to the interlocking of the four pairs of parallel ribbons at their overlap area. Hence, the periodically layout nanopores in the orthogonal-diagonal nanotexture can be well kept after relaxation. In particular, for a folded nanotexture in a gas medium at room temperature, it can expand to its initial configuration in which the nanopores simultaneously becoming regular. The features extend the potential applications of the new two-dimensional material as a candidate of the membrane with a periodic layout of nanometer-sized pores.