Graphene and related materials in hierarchical fiber composites: production techniques and key industrial benefits

Fiber-reinforced composites (FRC) are nowadays one of the most widely used high-tech materials worldwide. In particular, sporting goods, sports cars and the wings and fuselages of airplanes are made of carbon fiber reinforced composites (CFRC). Today CFRC are a mature technology, but are still challenging materials. Their mechanical and electrical properties are very good along the fiber axis, but can be very poor perpendicular to it; weak interaction of the fiber surface with the polymer matrix leads to crack propagation and delamination; fiber production includes high-temperature treatments, leading to high costs. Scientific work performed in recent years shows that the performance of CFRC can be improved by addition of graphene or related 2-dimensional materials (GRM). Graphene is a promising additive for CFRC because: 1) Its all-carbon aromatic structure is similar to the one of CF. 2) Its 2-dimensional shape, high aspect ratio, high flexibility and mechanical strength allow it to be used as a coating on the surface of CF, or as a mechanical/electrical connection between different CF layers. 3) Its tunable surface chemistry allows its interaction to be enhanced with either the CF or the polymer matrix used in the composite and 4) in contrast to CF or nanotubes, it is easily produced on a large scale at room temperature, without metal catalysts. Here, we summarize the key strategic advantages that could be obtained in this way, and some of the recent results that have been obtained in this field within the Graphene Flagship project and worldwide.