Evaluation of the "self-healing", corrosion inhibitive effect of nanocontainers, micro- and nanocapsules in anticorrosive paints

Within this work, special nanocontainers, which act as reservoirs for the exchange of corrosive ions, as well as micro- and nanocapsules, which contain corrosion inhibitors, were introduced in a anticorrosive primer formulation. Such primers applied on steel substrates were exposed to a thermo-cyclic electrolytic (TCE) loading, whereby the electrolyte impacted intact as well as reproducibly injured areas separately. Electrochemical impedance spectroscopy (EIS) was used for the characterization of the corrosion inhibitive effect as well as the impact on barrier properties and delamination resistance caused by the presence of the particles. Poor effect was found for some small nanocapsules, wheras larger ones showed observable anticorrosive impact in injured areas. These capsules, however, affected the barrier properties and the adhesion of the primer. The nanocontainers used exhibited mean corrosion inhibitive effect, however, apparently improved the adhesion.