Cathodic disbonding of paint films-transport of charge

Advances in corrosion protection by organic coatings: What we know and what we would like to know

“…A correlation of disbonding rate with cation mobility or diffusivity for coatings under cathodic protection was first noted by Leidheiser 18 who found, for model polybutadiene coatings, that ionic diffusion through the film thickness accounted for the observed disbonding kinetics. A similar finding was confirmed by Skar and Steinsmo 19 and this makes sense because cathodic substrate polarisation encourages electromigration of cations through the coating to the substrate. However, for defects that arise as a result of service damage (i.e.…”

Influence of substrate topography on cathodic delamination of anticorrosive coatings

“…along the coating-steel interface, through the intact coating and through the coating in the delaminated region as illustrated in Figure 1 [26]. If the cations are transported through the coating, they may upon entering the coating-steel interface be transported along the coating-steel interface because the transport of ions along the coating-steel interface has been found to be much faster than that through the coating [27].…”

“…In general, the transport of cations along the coating-steel interface from the defect to the delamination front is considered the rate determining step in cathodic delamination [6,8]. However, transport perpendicular to the coating has also been suggested as the rate determining step [26]. Other studies show that cations might be transported through the coating when the coated steel is under cathodic polarisation [28][29][30].…”

Effect of N2O Flow Rate on Reliability of SiOxFilms Deposited by SiH4–N2O Gas Mixture Plasma

“…The mechanisms of adhesion degradation caused by high pH are oxide reduction, alkaline hydrolysis of the polymer, and weakening of the interface. 8) Two common cathodic reactions are the major pathways for cathodic delamination in the presence of air and moisture as follows: [9][10][11][12]…”