Modification with thiols facilitates the integration into the zinc
“This is an intelligent protective system that automatically realises when and where corrosion happens, becomes active and stops again when the respective spot is healed”, explains Dr. Rohwerder, group leader in the department of Interface Chemistry and Surface Engineering. It works like a scratch in the skin: it is detected, healed and the initial status is restored. For preparing these smart coatings, three work steps must be performed: loading of the silica microcapsules with the inhibitor, sealing them to avoid premature leaching and finally incorporating the capsules into the zinc layer. The sealing procedure, however, has of course an immense influence on the release kinetics. By rinsing with water glass solution, the release is steady and slow. The incorporation into the zinc layer is the most difficult part. Unmodified, the hydrophilic particles are repulsed by the zinc and only adsorb on the surface. Tabrisur Rahman Khan, a PhD student from Bangladesh, has now fixed the problem. He modifies the particles with zinc affine functional groups, such as thiols, which make the solvation feasible.
Max-Planck & Fraunhofer collaboration on intelligent corrosion coatings
Everything solved? Well, not completely. For efficient protection, a higher loading of the pores with the inhibitor must be realised. This is the focus of current research. Additionally, the concept of intelligent corrosion coatings has been expanded to systems with polymer coatings. The joint project ASKORR (Aktive Schichten für den Korrosionsschutz, active coatings for corrosion protection) is a successful collaboration between the Max-Planck and the Fraunhofer Society in this field. Two Max-Planck and two Fraunhofer Institutes are sharing their competences with respect to nanocomposite coatings, agent containers, zinc coatings and the analysis of effective mechanisms in order to improve the protective coatings. “It is a huge challenge, but present results look very promising”, states Rohwerder. 1 Gesellschaft für Korrosionsforschung<img src=”data:image/png;