Mechanics of the scrolling and folding of graphene

Abstract

The competition between the out-of-plane rigidity and the van der Waals interaction leads to the scrolled and folded structural configurations of graphene. These configuration changes, as compared with the initially planar geometry, significantly affect the electronic, optical and mechanical properties of graphene, promising exciting applications in graphene-nanoelectronics. We propose a finite-deformation theoretical model, in which no presumed assumptions on the geometries of deformed configurations are required. Both the predicted deformed profiles and the critical conditions show great agreements with molecular dynamics simulations results when compared with existing studies with simple geometrical assumptions. Moreover, MD simulations are performed to explore the morphology transitions between different configurations. It is observed that the folded configuration is energetically favorable for a short graphene sheet, while a long graphene sheet tends to scroll. Of particular interest, we observe the morphology transition from a Fermat scroll to the Archimedean scroll for the bi-scrolled graphene. These findings are useful for understanding the stability of graphene and may provide guidance to the design of programmable graphene-nanoelectronics.

How to unloop a self-adherent sheet

“…Therefore, we expect that our findings will be applicable to a broader range of problems involving loops and blisters. These phenomena appear in, e.g., coatings, flexible electronics and during the exfoliation of graphene sheets [30], for which narrow adhesive zones plays a crucial role in the appearance of folded and scrolled loop topologies [31,32].…”

Quantifying respiratory tract deposition of airborne graphene nanoplatelets: The impact of plate-like shape and folded structure

“…The folded structure was owing to the out-of-plane flexibility and large lateral dimension to thickness ratio of GNPs. Folding was triggered by mechanical stimulus and stabilized via van der Waals forces [26,27]. The folding frequency based on GNPs lateral size was also estimated.…”

“…Because of the large lateral dimension to thickness ratio and out-of-plane flexibility, GNPs are easily warped in the out-of-plane direction. This unique property and van der Waals attraction between graphene sheets facilitate the self-folded configuration [26]. The study about folding could be traced back to the 1990s, where folding was observed due to the friction between scanning probe microscopy tips and the surface of pyrolytic graphite.…”

Fibrillation of Pristine 2D Materials by 2D‐Confined Electrolytes

“…[1,2,3] Their intrinsic crystalline structure implies that any configuration different from their flat 2D sheets result in different allotropic structures, with great implications for their electronic, optical and mechanical properties. [4][5][6] This direct structure-property relationship further expands the applications of 2D materials as intelligent materials, e.g., simple corrugations allow for proton transport, [7] and scrolling dramatically affects the adhesion properties [8] and out-of-plane stiffness in graphene. [9] Actually, folded or scrolled structures are energetically favored due to interlayer adhesion, but a kinetic barrier is usually present and the conformation changes cause uneven strain distributions within the 2D structures.…”