Few layer graphene from mechanical exfoliation of graphite based materials. Structure-dependent characteristics

TL;DR

This paper introduces an improved, scalable mechanical exfoliation method for producing high-quality few-layer graphene, comparing its properties with pencil lead-derived graphene and exploring applications in nanocomposites and electronics.

Contribution

The authors develop a simplified, high-scale exfoliation process yielding graphene with enhanced morphology and properties, and compare it to pencil lead-derived graphene for various applications.

Findings

Higher aspect ratio and transparency-conductivity in new FLG

Enhanced elongation at break in polymer composites

Lead FLG nanocomposites exhibit excellent gas barrier properties

Abstract

We present a high scale method to produce few layer graphene (FLG) based on the mechanical exfoliation of graphite and compare the obtained FLG with the one reported earlier arising from pencil lead ablation. Several things are modified and improved in the new approach. The purification and the ablation set_up are simplified, and the morphology of the FLG is modified and improved in view of some applications. The morphology dependent properties of FLGs, lead FLG and graphite FLG, are investigated as conductive layers and in nanocomposites. Newly obtained FLG has higher aspect ratio (high lateral size vs. thickness,higher 2D aspect) which is reflected by an enhanced transparency_conductivity features of the layer (film) and an elongation at break behavior in the polymer composites. On the contrary, the nanocomposite containing lead FLG shows for instance excellent gas barrier properties due to the multistep structure of lead FLG flakes. Such structure exhibits less 2D and more 3D character, which can be highly suitable for applications where the presence of active, reactive edges is beneficial ( in catalysis or supercapacitors electrodes). Nuclear reaction analysis is employed to investigate the morphology of graphite FLG film.