The influence of three different intercalation techniques on the microstructure of exfoliated graphite
Loading...
Date
Authors
Van Heerden, Xandra
Badenhorst, Heinrich
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
The characteristics of exfoliated graphite derived from three intercalation methods: gas
phase intercalation of iron (III) chloride, modified Hummers method and an electrochemical
technique, were compared.
Despite the absence of strong oxidisers the electrochemical method produced a material
which is very similar to that of the modified Hummers method in virtually every respect.
These both produced a graphite oxide based material whilst the gas phase method resulted
in a stage 1 intercalation compound. The different materials demonstrated very distinctive
exfoliation behaviour.
The gas phase material exhibits 3% mass loss during expansion but has a large amount of
residual intercalant. The graphite oxide based methods result in mass loss of up to 25% in
the expansion zone. For all three samples the residual impurities lead to a reduction in
oxidative resistance. Once removed all samples exhibit nearly identical oxidation behaviour.
All three methods delivered graphite nanoplatelets with a very high aspect ratio through
considerable expansion. Surprisingly the gas phase method caused persistent residual
damage. All three methods yielded a product with varying levels of basal and edge damage,
but the purified Hummers material exhibited marginally more ‘ideal’ characteristics. The
simplest but still effective technique was found to be the electrochemical approach.
Description
Keywords
Microstructure, Exfoliated graphite, Gas phase intercalation of iron (III) chloride, Modified Hummers method, Electrochemical technique
Sustainable Development Goals
Citation
Van Heerden, X & Badenhorst, H 2015, 'The influence of three different intercalation techniques on the microstructure of exfoliated graphite', Carbon, vol. 88, pp. 173-184.