ENVIRAL® acquires licence for smart pigments for environmentally friendly, sustainable anticorrosion coatings

Corrosion involves an adverse, quality-reducing change in a material emanating from the surface. It is caused by an undesirable, usually electrochemical, reaction. It is estimated that corrosion costs the world economy 3.3 trillion dollars a year ? and this figure only includes direct costs, such as maintenance, repair and monitoring. There are also major indirect costs: personal injury, damage due to the escape of environmentally harmful liquids, and lost production, to name just a few.

The purpose of anticorrosion coatings is to prevent such damage from happening. To this end, layers of paint, enamel, rubber or metal are applied to prevent contact between materials and corrosive agents such as water and air. Another approach is to bring a material into contact with a more active metal that preferentially undergoes corrosion, so that the material itself is spared. Such sacrificial anodes can be found, for example, on fully galvanized car bodies. Unfortunately, conventional anticorrosion coatings often contain harmful chemicals, including carcinogenic chromium (VI) salts and other toxic heavy metal compounds. ENVIRAL® has set itself the goal of replacing conventional anticorrosion coatings with its new, sustainable and environmentally friendly technology.

Based on research carried out by the Max Planck Institute of Colloids and Interfaces, ENVIRAL® promotes the development, production and marketing of smart pigments, i.e. advanced micro- and nanoadditives for highly effective, environmentally friendly anticorrosion coatings. The model for the technology is the self-healing mechanism of the human skin. Based on this, an innovative process for functionalizing anticorrosive coatings was developed which enables them to “heal” if they are damaged. For this purpose, tiny micro- and nanovessels are filled with organic corrosion inhibitors. The vessels are encapsulated with a polyelectrolyte layer and then embedded in a protective anticorrosion coating. If the protective coating undergoes damage that exposes it to corrosive influences, e.g. scratches or cracks, corrosion-induced pH changes at the damaged site cause the embedded vessels to open and release the corrosion inhibitor. As a result, the damaged area is again immediately protected, and the corrosion reaction is nipped in the bud. Subsequent normalization of the pH seals the polyelectrolyte shell around the nanovessel again, and no further corrosion inhibitor can escape.

The decisive advantage of such functionalized protective coatings is their active feedback with the corrosion reaction. The rust inhibitor is released only at the damaged site and only in the amount required to achieve corrosion prevention. The benefits are longer-lasting protection and much greater sustainability of the coatings. Another advantage of the innovative approach is its versatility. The size of the micro- and nanovessels, the properties of the shell, the nature of the contained substances and the release mechanisms can all be adapted to the application at hand.

The technology has been licensed exclusively to ENVIRAL® by Max Planck Innovation, the technology transfer organization of the Max Planck Society. “We are pleased that the research findings of the Max Planck Institute of Colloids and Interfaces have now been translated into practical applications by an industry specialist and long-term cooperation partner,” says Dr. Lars Cuypers, Senior Patent and License Manager at Max Planck Innovation.