Fs Parameters Research Articles

The study of diffusion of media in the organic coating films by BAW admittance analysis

The permeation of water and corrosive species in coating films is very important for the corrosion protection by organic coatings. As a new method for the study of diffusion of media in coating films, bulk acoustic wave (BAW) admittance analysis has been proposed in this article. Real-time information on the change of the film mass, mechanic property of the layer, and the permeation process of the media can be provided simultaneously by the parameters of BAW admittance analysis, fs (series resonant frequency), ΔL1 (inductance variance), R1 (resistance), Q (quality factor), and Cs (film capacitance). The diffusion behavior of media and the corresponding film stability can be described by the following parameters: D (diffusion coefficient), P (permeation coefficient), S (the solubility of media), and SC (the swelling coefficient of the coating layer). © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2283–2290, 1998