Composite materials are increasingly used due to their low density with superior mechanical properties. One of the major problems of composite materials is the lack of electrical conductivity, which is an important factor in terms of de-icing applications and lightning strike protection. Currently high amounts of additives like graphite have to be added to sufficiently promote the electrical conductivity. This comes at the prize of deteriorating the mechanical properties of the material.
Graphene based additives allow to sufficiently increase the conductivity while using significantly less amount of additive. These lower amounts do not deteriorate the mechanical properties of the composite but rather increase the strength of the material. This opens the door to implement electrical functionalities within structural parts leading to weight decrease and subsequently a significant reduction of the aircrafts CO2-emission.
Graphene oxide flakes as well as differently modified graphene oxide species are dispersed within epoxy composites and implemented in the form of structural bulk composites or laminates. Typical aeronautical epoxy resins are used to guarantee the possibility of implementation within currently used aeronautical composites. Implementation as a coating on composite and aluminium alloys are also considered for application.
The figures below show examples of graphene-based epoxy samples. Both the coating of alumina substrates and the production of GO/epoxy-laminates is possible. These specimen are further tested regarding the properties for de-icing, lightning strike protection, flame inhibition and water impermeability.
Various characterisation techniques are used for the different applications. The gallery below shows some impressions of functionality tests and chemical characterisation, which are executed to fully understand the material.