Research profile: Chris Ewels

My research is in the field of atomic scale computer modelling of carbon nanomaterials. The incredible versatility in bonding of carbon means that at the nanoscale there is a whole zoology of interesting and unusual carbon nanostructures, each with its own properties and peculiarities. The field received an enormous boost kick-started by the arrival of graphene in 2004 and the subsequent Nobel Prize in 2010, resulting in a revolution in our understanding of the complexities and possibilities of carbon. But at the same time there has been a quieter, but no less profound revolution in the experimental and theoretical tools we have available for characterising these exciting new materials. 

 

The introduction and now increasingly widespread adoption of aberration correction for electron microscopy means that we are no longer able to simply image the form of these carbon nanomaterials, we can now identify the precise atomic structure of edges, defects such as dislocations, and even individual impurity and defect atoms. At the same time new advances in quantum chemical theoretical techniques and more powerful computing means that computer modelling is moving away from the abstracted, idealised models of the past towards simulation of realistic systems. This allows us, for example, to incorporate the effect of interactions with an underlying substrate, or absorbent gas molecules on these carbon nanomaterials. Spectroscopic characterisation techniques are becoming increasingly sophisticated, with spatially resolved optical spectroscopy making use of near field techniques, improved resolution EELS and new advances in X-ray spectroscopy amongst many others. 

 

These advances have ushered in a new world for those of us working in atomic scale computer modelling. In the not-so-distant past, verification of our limited structural models required sometimes tortuous and indirect comparison with bulk or large scale data. But now the convergence in scale between experiment and theory means they are finally starting to work at the same scale. This is demonstrated by the recent boom in collaborative experimental and theoretical papers able to elegantly demonstrate the complex and wonderful dance of carbon atoms in these new materials. 

 

This is a trend that will only continue. The new era of direct collaboration between theoretical modelling and experimental characterisation is leading to rapid acceleration in our understanding of the unique properties of materials such as graphene and nanotubes, and importantly, allowing us to directly link these to specific atomic-scale behaviour.   This should massively accelerate our ability to fine-tune the chemistry and composition of graphene nanoribbons, nanotubes, fullerenes and all their nanoscale carbon relatives in order to directly tailor their properties to the required task, be it gas sensing, catalysis and storage, nanoelectronics, composites, or any of the myriad other applications awaiting. For the field of carbon nanomaterials, these are interesting times.

 

Chris Ewels