Graphene Flagship Partnering Project MECHANIC explores elusive interactions in graphene-enhanced composites

Funded by the FLAG-ERA Joint Transnational Call 2017, Graphene Flagship Partnering Project MECHANIC uses modelling and computer simulations to investigate what happens when graphene-based materials are incorporated into polymer composites. Project Leader Andreas Isacsson, Professor of Condensed Matter and Materials Theory at Graphene Flagship partner Chalmers Institute of Technology, Sweden, explains how their methods will lay the foundations for new composites to be characterised and validated in the future.

Polymer composites are common construction materials, and Graphene Flagship scientists are ever-on-the-hunt for new ways to improve their properties using graphene and layered materials. In particular, scientists may wish to design materials with tailored electrical or physical properties to efficiently transport heat or current. Graphene oxide (GO) and reduced graphene oxide (RGO) are excellent contenders, as they are cheap and widely available.

“Before we can decide on the best way to incorporate graphene and related materials into polymer composites, we first need to understand how well the material will conduct electricity and heat, and the factors influencing this,” begins Isacsson.

“MECHANIC’s core philosophy is to use computational methods to better understand the interactions occurring when materials like GO and RGO are added to the mix,” he explains. Like the other Partnering Projects, MECHANIC is a truly European collaboration

“We use what’s called a ‘multi-scale’ approach, starting at the smallest scale – modelling atoms, their electrons and vibrations – gradually going up in size until we’re looking at wider structures,” he continues.

Within the project, scientists at Graphene Flagship partner Catholic University of Louvain, Belgium, investigate the effect of imperfections on a material’s atomistic structure. Researchers at Graphene Flagship Partner Chalmers Institute of Technology evaluate the forces exerted by defects on individual atoms. Then, on a larger scale, Graphene Flagship partner ICN2, Spain, simulates the removal of unwanted functional groups to determine the effect on a composite’s overall structure on electronic and thermal properties in realistic models. Graphene Flagship Associated Member Izmir Institute of Technology complements the simulation chain with device modelling.

“We found that in these composites, electrons find a path that would otherwise have been blocked by a layer of conductive material,” says Isacsson. These results are in-agreement with experiments, allowing them to validate their methodology to the point that it is fully reproducible.

“Thanks to our work, there now exists a numerical framework to evaluate heat and charge transport in disordered composite materials, which has been fully validated and can be used in the future,” Isacsson concludes.

MECHANIC has become instrumental to providing guidelines for companies, such as Graphene Flagship partner Avanzare Innovacion Tecnologica SL, the Spanish company is the largest producer of graphene-based composites. The importance of the project is also reflected by complementary experimental research performed at the Italian Institute of Organic Synthesis and Photoreactivity (ISOF) of the National Research Council of Italy (CNR). This illustrates how FLAG-ERA sparked inclusive synergies in Europe by marrying research activities from Flagship and FLAG-ERA projects