Designing fouling release coatings for marine applications
Axel Rosenhahn, Ruhr-University Bochum, Bochum, Germany
Novel materials with environmentally benign fouling-release properties have been developed during the last years to substitute toxic coatings. The concept relies on weakening the attachment of adherent fouling organisms like diatoms or barnacles so that a fast moving ship is capable to self-clean by the shear stress generated by its motion through the ocean. Assessment of fouling release coating's efficiency is of key relevance for the down selection of chemistries. We developed a laboratory assay based on a parallel plate flow chamber that allows testing of coating candidates against algal cell adhesion with precisely controlled flow rates and cell concentrations. Using self-assembled monolayers as model surfaces and diatoms as model organisms we were able to show that the adhesion strength correlates with the accumulation dynamics if an appropriate wall shear stress is applied. Selected examples will be given out of our current research projects on polyelectrolyte multilayers, sol-gel deposited coatings, photocrosslinked zwitterionic methacrylates, and amphiphilic silicones.