Researchers show the amphipathic nature of graphene flakes and examine their potential for use as surfactant

Researchers at Cranfield University and the University of Cambridge in the UK, Institut Pasteur in France, Silesian University of Technology in Poland and UniversIti Teknologi PETRONAS in Malaysia have found that at a particular size (below 1-micron lateral size), it is possible to achieve amphiphilic behaviour in graphene. This graphene flake attracts water at its edges but repels it on its surface, making it a new generation of surfactant that can stabilize oil and water mixtures.

In a statement, Krzysztof Koziol, Professor of Composites Engineering and Head of the Enhanced Composites and Structures Centre at Cranfield University said, This new finding, and clear experimental demonstration of surfactant behavior of graphene, has exciting possibilities for many industrial applications. We produced pristine graphene flakes, without application of any surface treatment, at a specific size which can stabilize water/oil emulsions even under high pressure and high temperature... Unlike traditional surfactants which degrade and are often corrosive, graphene opens new level of material resistance, can operate at high pressures, combined with high temperatures and even radiation conditions; and we can recycle it. Graphene has the potential to become a truly high-performance surfactant.

According to Cranfield University, the qualities of this graphene flake make it an ideal material to be combined with water and used as a surfactant in environmentally friendly extraction of minerals, crude oil and other ores from rock. There is also need for better quality surfactants as plasticizers for fluid concrete, additives in flameproofing and waterproofing as well as lubricants in drilling fluids.

The surfactants currently in use are corrosive and degrade under intense heat and pressured environments.

Mike Payne, Professor of Computational Physics at Cambridge University, who was one of the co-researchers, said: There is an enormous volume of scientific research on graphene. In some ways this is to be applauded but it can also lead to conflicting results in the literature as in the present example of whether graphene flakes are hydrophobic or amphiphilic. Our work combines exciting experiments on a well characterized material with a range of theoretical simulations, including quantum mechanical calculations. Together they provide a detailed understanding of the properties of the graphene flakes and a definitive answer to this question.

Cranfield University is now looking to commercialize these findings.