Corrosion protection by organic coatings: onset of disbonding and delamination at the buried organic-inorganic interface

Madelat, N. (Presenter), Negar Khayatan (Contributor), Wouters, B. (Contributor), Hauffman, T. (Contributor), Terryn, H. (Contributor), Michael Rohwerder (Contributor)

Activity: Talk or presentationTalk or presentation at a conference

Description

Since organic coatings have a significant role in protecting metals from their surrounding atmosphere, it is of a great importance to increase the efficiency and durability of such hybrid structures. To achieve this aim, it should be mentioned that the formation and degradation of the bonds happening at the buried interface (solid/solid interface) is a limiting factor for this durability. In order to determine the onset of failure of the protection, insights in the molecular interfacial phenomena in technological relevant conditions is essential. Especially in the case of cathodic delamination as the dominant failure mechanism for organic coating covered iron and zinc substrates, the interactions governing the onset and progress of the delamination front are far from understood.

The existing lack of knowledge on hybrid structures relates to the difficulty of studying buried interfaces. In this work, two in-situ techniques are combined to probe the cathodic failure mechanism of iron/zinc substrates covered with a multiple micrometer-thick coatings to mimic realistic complex systems. In-situ infrared spectroscopy in a Kretschmann geometry provide us with the ability to study the interfacial interactions at the buried interface of thick coating-metal systems in aqueous environments. With this methodology, changes of the bonds as a function of the ingress of electrolyte and time will be monitored. In parallel, the delamination of the coating on iron/zinc substrates is followed up by Scanning Kelvin Probe. In this way, insights in which parameters control the progress of the delamination front together with the kinetics of failure are achieved.

Combining both techniques provide key information to pinpoint the actual interactions governing the onset of failure and the ones leading to the progression of it.
Period7 Sep 2020
Event titleVirtual Eurocorr 2020
Event typeConference
Degree of RecognitionInternational