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 advantage of smart pigments is the active feedback with the corrosion reaction, so that the corrosion inhibitor is released only if corrosion actually occurs and only in a limited area. Moreover, encapsulating the corrosion inhibitor prevents it from interacting with the coating matrix. This makes it possible to use environmentally friendly inhibitors, which if not encapsulated would weaken the coating. In addition, while maintaining the same anticorrosion effect, smart pigments allow much thinner coatings to be used, thus reducing material consumption and the number of coating cycles, which also reduces the environmental impact of the coating process itself,” says Rainer Rogovits, Managing Director of ENVIRAL® Oberflächenveredelung GmbH. 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.
About ENVIRAL® Oberflächenveredelung GmbH
ENVIRAL® Oberflächenveredelung GmbH was established in 1994 and began production at the Niemegk site in 1996. Since then the company has developed into a nationally and internationally reputed service provider in the field of surface coatings with a focus on architectural and industrial powder coatings. The middle-size company, which has also had a site in Pöttelsdorf in the state of Burgenland in Austria since 2007, provides its customers in industry, the trades, façade construction and metal structural engineering with powder coating systems that meet the most exacting quality demands. In addition to their appealing appearance and an almost infinite range of colours and textures, ENVIRAL powder coatings are characterized by physical resistance and excellent anticorrosion properties. The range of materials extends from aluminium, steel and galvanized steel to glass, paper and plastic film.
The ENVIRAL® Nanolab Department develops and manufactures SmartCorr additives for the production of wet and powder paints, and also tests products. ENVIRAL® seeks selected development partnerships with universities and research institutions. www.enviral.de
About the Max Planck Institute of Colloids and Interfaces
The Max Planck Institute of Colloids and Interfaces was founded in 1992. It is managed on a collegial basis and is divided into the Biomaterials, Biomolecular Systems, Colloidal Chemistry, and Theory & Bio-Systems Departments, the Mechano(bio)chemistry Research Group and the Emeritus Group (Interfaces). Current research topics include polymer films, membranes, organic and inorganic nanostructures, microcapsules, biomineralization, nano- and microreactors, molecular motors and filaments, and the chemistry and biology of carbohydrates.
Do you want to receive our newsletter and press releases?
Phone: (089) 290919-30