Wrinkled few-layer graphene as highly efficient load bearer

TL;DR

This study demonstrates that large wavelength wrinkles in few-layer graphene significantly improve its load-bearing capacity by enhancing interfacial shear stress, challenging the belief that wrinkles weaken 2D materials.

Contribution

It reveals that extensive wrinkling in few-layer graphene enhances stress transfer, offering a new approach to designing more effective graphene-based composites.

Findings

Wrinkled graphene shows increased load-bearing capacity.

Wrinkles enhance interfacial shear stress during strain.

Wrinkling can be used to improve composite materials.

Abstract

Multilayered graphitic materials are not suitable as load-bearers due to their inherent weak interlayer bonding (for example, graphite is a solid lubricant in certain applications). This situation is largely improved when two-dimensional (2-D) materials such as a monolayer (SLG) graphene are employed. The downside in these cases is the presence of thermally or mechanically induced wrinkles which are ubiquitous in 2-D materials. Here we set out to examine the effect of extensive large wavelength/ amplitude wrinkling on the stress transfer capabilities of exfoliated simply-supported graphene flakes. Contrary to common belief we present clear evidence that this type of "corrugation" enhances the load bearing capacity of few-layer graphene as compared to 'flat' specimens. This effect is the result of the significant increase of the graphene/polymer interfacial shear stress per increment of applied strain due to wrinkling and paves the way for designing affordable graphene composites with highly improved stress-transfer efficiency.