Nanostructured coatings improve performance
Coatings can improve mechanical, optical and even aerodynamic properties of components in a variety of industries. However, changes in surface structure can significantly impair performance and thus increase operating and maintenance costs. For example, surface fouling and erosion increase the fuel consumption of aircraft and marine vessels and reduce the power output of wind turbines. Characterisation of the sub-micron features currently requires time-consuming and sophisticated laboratory-based equipment. Therefore, scientists launched the EU-funded project NATURAL (Standardised metrology of nano-structured coatings with low surface energy) to develop a rapid non-destructive methodology for correlating surface structure on the nanoscale with functional performance in the field. The technology represents the first generation of metrology standards that relate structure to performance, allowing assessment of fitness-for-purpose. Project partners developed short-wavelength, high-resolution laser profiling methods for rapid surface characterisation of the coarse nanoscale structure of large areas. Nanoscale measures were correlated with tribology and fluid flow analysis at the macroscale. This enabled the consortium to make recommendations for new standards relating surface nanomorphology to functional performance, and ultimately to lifetime prediction. Scientists characterised two different coatings, both two-part polyurethanes, by applying them to glass fibre substrates to provide a baseline. One was a commercial benchmark coating that was fully formulated and commonly used by wind blade manufacturers. It employed a high-performance resin system that is an industry standard and also has a number of fillers. The second (model) system had no fillers to more quickly elucidate the effects of nanoparticles. A number of nanoparticles were synthesised, functionalised and incorporated into the coatings. The team finalised the design of the prototype nanoscale characterisation measurement system for non-destructive evaluation in the field. NATURAL's enhanced understanding of the effects of nanostructure on performance and its non-destructive metrology system will lead to new standards, improved coatings and a boost to numerous sectors of the economy. This is thanks to improved deposition techniques developed by the project as well portable instrumentation, which allow for greater ease of use. Additional benefits include the reduced cost of repair of components and improved deposition techniques resulting in significant improvement of coating quality. This will result in lower energy bills for the consumer. Moreover, increased efficiency means less pollution through a reduction in the need to rely on-non-renewable energy production.
Keywords
Nanostructured coatings, NATURAL, metrology, laser profiling, nanoparticle
