In recent years, requirements for modern coatings have dramatically increased. Besides optical appearance, new functionalities like improved mechanical properties, anti-static behavior or electrical conductivity are desired. To achieve this, several materials can be incorporated into the coating film. For enhanced electrical conductivity, substances like copper or silver particles, conductive organic polymers, or carbon black can be used. In many cases, such materials have to be used in the form of nanoparticles to achieve even distribution inside the film and low percolation thresholds.
There are several synthesis routes known to produce such nanoparticles, but they often result in either low yields or in materials that need further processing to show optimum performance. This can lead to high material prices, and in combination with increasing raw material costs, the overall costs can become prohibitive for some applications. An example of this would be the use of silver. The average price of silver has been steadily increasing during the last few years, and silver nanoparticles are even more expensive. For coatings applications, most companies now focus on non-metallic compounds, like carbon materials, to achieve electrical conductivity.