Research in corrosion protection has been increasing since the 18th century, especially with respect to steel.
The microcapsules filled with corrosion
inhibitor are released when the steel
sheet is cut. Quelle: MPIE
Galvanizing is a common protective means, but during the production process initial corrosive spots are formed right at the cut-edge. The idea that is developed at the MPIE is to incorporate microcapsules, which are filled with corrosion inhibitor, e.g. polyphosphomolybdate, into the zinc coating. As soon as the steel sheet is cut, the zinc starts to corrode and dissolve.
This is the starting shot for the intelligent, second protective system: the capsules are released from the zinc onto the steel and smeared along the surface by the cutting device. The inhibitor can be released and thus protects the steel surface.
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 KorrosionsforschungYasmin A. Salem, M.A.
Yasmin A. Salem | MPIE
Two intelligent vehicles are better than one
04.10.2017 | Ecole Polytechnique Fédérale de Lausanne
The Future of Mobility: tomorrow’s ways of getting from A to B
07.09.2017 | Fraunhofer-Institut für Angewandte Informationstechnik FIT
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
It's possible to produce hydrogen to power fuel cells by extracting the gas from seawater, but the electricity required to do it makes the process costly. UCF...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Physics and Astronomy
17.10.2017 | Life Sciences