Morphology and Mechanism of Benign Inhibitors
Final rept. 28 Jan 2008-29 Jan 2009
CINCINNATI UNIV OH
Pagination or Media Count:
Neutron and x-ray reflectivity are used to determine the composition profile of vanadate and trivalent chromium process TCP inhibitor films. In both cases, the films have a complex structure consisting of at least two layers. For vanadate films, a porous, hydrophilic layer exists at the interface between the film and the metal substrate. For TCP films, the interfacial layer is very thin and dense if the film is deposited electrochemically. The films also differ in hydration. Vanadate films are un-hydrated whereas TCP films exist as hydrates of the form Crf2O3-4H2O. In both cases, the bulk of the films is not fully dense. Densification is observed, however, at high temperature and when dried after exposure to liquid water. The differences in film morphology imply different mechanisms of film formation. Mechanisms are described that are consistent with the observations.
- Inorganic Chemistry