Electrochemical impedance spectroscopy of multi-layer epoxy coatings in NaCl solution
多道环氧涂层在NaCl溶液中的电化学阻抗谱

The diffusion behavior of water through epoxy coatings as a function of the film thickness and the painting number was studied by electrochemical impedance spectroscopy (EIS) techniques. The experimental results showed that, in 3.5 wt.% NaCl solution, the diffusion process of water through multi-layer organic coatings with good barrier performance followed the ideal Fick's law in the initial period. The corresponding diffusion coefficient was also derived and the dielectric constant of the dry coatings (ed) was found to be 4.2. The resistance to medium permeation of the coatings increased with increasing of film thickness and the number of coats.