Understanding Graphene Nanoplatelet Composite Alignment

Graphene nanoplatelets have been used effectively to demonstrate barrier properties in coating applications reducing the level of water penetration enhancing the level of corrosion resistance compared to other barrier pigments. The application of improved barrier properties has importance beyond corrosion in the development of new packaging technologies and electronics industry where sensitive electronics may require water or chemical protection. Maximisation of the performance of the nanoplatelets is dependent on their alignment in the coating and is impacted by the cure conditions used. Elevated temperature curing with associated rapid increase in viscosity and associated gelation is likely to increase the level of disorder, reducing the impact of Graphene addition. Various formulating approaches might be considered to mitigate these effects but an understanding of the degree of alignment and arising in an ambient cure and relative effects of change in surface tension and gelation is required. Currently tools neither Scanning Electron Microscopy nor Transmission Electron Microscopy are able to provide a measure of the alignment seen in processing films at different temperatures and rates of cure. The development of a method of measurement to determine alignment of Graphene nanoplatelets in a film would enable an understanding of this problem and facilitate methods to overcome the observed problem opening these and additional markets (electrical and thermal conductivity ) where platelet alignment is a key requirement of performance.