Titre : |
Method for measuring water diffusion in a coating applied to a substrate |
Type de document : |
texte imprimé |
Auteurs : |
T. Nguyen, Auteur ; D. Bentz, Auteur ; E. Byrd, Auteur |
Année de publication : |
1995 |
Article en page(s) : |
p. 37-46 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Couches minces Diffusion (physique) Epoxydes Fourier, Spectroscopie infrarouge à transformée de Perméabilité Polyalkydes Réflectance Revêtements
|
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
A method based on Fourier transform infrared-multiple internal reflection (FTIR-MIR) spectroscopy was developed for measuring the apparent diffusion coefficient of water in a coating applied to a substrate. The method requires an appliction of a coating of any thickness on an internal reflection element, which serves as the substrate, with the attachment of a water chamber to the coated specimen. Water is introduced to the chamber and FTIR-MIR spectra are collected automatically without disturbing the specimen or the instrument. The amount of water at the coating/substrate interface was determined using a model based on the theory of internal reflection spectroscopy. A mass-time curve for water at the interface is established, which provides the time-lag value, the time required for water to diffuse through the coating film and reach the interface. The diffusion coefficient (D) is then determined by the time-lag equation. For thick coating films (>25 μm), D may be estimated from the FTIR-MIR in situ intensity data only. The sensitivity of FTIR-MIR spectroscopy and the strong FTIR absorption of water molecules make this an ideal method for measuring the diffusivity of liquid water through a coating applied to a substrate. |
Note de contenu : |
- BACKGROUND : Water diffusion in coatings - Fourier transform infrared-multiple internal reflection spectroscopy
- RESULTS AND DISCUSSION : Amount of water at the coating/substrate interface - Diffusion coefficient of water in coatings applied to a substrate |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18511 |
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 67, N° 844 (05/1995) . - p. 37-46