Monitoring initial contact of UV-cured organic coatings with aqueous solutions using odd random phase multisine electrochemical impedance spectroscopy

In this work, a new methodology is developed to study the initial behaviour of model organic coatings shortly after coming into contact with an aqueous solution, using odd random phase electrochemical impedance spectroscopy (ORP-EIS). The impedance results are resolved over time via the calculation of the instantaneous impedance and fitted with a physically meaningful equivalent circuit. Many physical parameters could be obtained, such as the rapid water uptake, the resistivity of the coatings and the penetration depth of ions in the coatings. The fitting results were verified using differential scanning calorimetry (DSC) and gravimetry.