Arc discharge, laser evaporation and chemical vapour deposition (CVD) are some of the most frequently used production processes for CNTs in industry.
In order to achieve adequate interaction between the nanotubes and the surrounding material, an important role is played not only by the structure of the individual nanotubes and the nature of their agglomerates (e.g. entangled CNTs) and the aggregates (e.g. SWCNTs or graphene layers that are stuck together), but also by the correct functionalisation of the surfaces.
Development efforts aim to achieve nanocarbon dispersions in which the potentials of the material are implemented efficiently. This requires the optimisation of technologies such as functionalisation (for optimum compatibility to the respective matrix) and dispersion (for homogeneous distribution and/or separation of the CNTs in the matrix). Increasing the mechanical strength is of paramount importance in wind-turbine applications.
High mechanical strength can be achieved in wind-turbine blades by using CNT-epoxy systems. At the same time, these are lighter than traditional systems. This is important because the length of wind turbines' rotor blades is restricted by their weight. Furthermore, the blades can be prevented from icing up by using electrically heated CNT-based coatings.
Given the increasing scarcity of fossil-based raw materials, and the negative environmental implications, wind turbines will make an important contribution to the future supply of energy.
They present an especially environmentally friendly form of renewable energy supply for the end consumer, since – compared to conventional power stations – they do not cause emissions of pollutants such as carbon dioxide, nitrogen oxides and sulphur dioxide.