Authors: O. Kachurina, E. Knobbe, T.L. Metroke, J.W. Ostrander, N.A. Kotov
Addresses: Sciperio, Inc., 5202-2 N. Richmond Hill Rd., Stillwater, OK, USA. ' Sciperio, Inc., 5202-2 N. Richmond Hill Rd., Stillwater, OK, USA. ' Department of Chemistry, Oklahoma State University, 107 PS-II, Stillwater, OK, USA. ' Department of Chemistry, Oklahoma State University, 107 PS-II, Stillwater, OK, USA. ' Department of Chemistry, Oklahoma State University, 107 PS-II, Stillwater, OK, USA
Abstract: Stratified systems comprising an inhibitor-doped layer-by-layer (LBL) clay-polyelectrolyte overcoated with a dense organically-modified silicate (Ormosil) are investigated as corrosion protectors for aluminium. As separate coatings, neither the LBL nor Ormosil films were found to provide adequate corrosion protection of the underlying metal. A combination of the two coating methods was found to produce a synergistic enhancement of corrosion resistance characteristics, as determined by using electrochemical techniques. This effect occurs due to the formation of sol-gel cross-linked LBL multilayers. Moreover, the LBL-sol-gel hybrid stratum seals the inhibitor ions into the polyelectrolyte layer, thereby producing a reservoir of corrosion inhibitors in the direct vicinity of the metal. Importantly, the LBL multilayers not affected by sol-gel promote lateral diffusion of an active corrosion inhibitor along the surface. Such a layered system can be considered as an example of performance optimisation by multilayer stratification of nanostructured materials. The combination of strong barrier functions, efficient corrosion inhibitor delivery, low cost of the components, and ecological compliance would be difficult to attain in traditional corrosion protection approaches.
Keywords: layer-by-layer assembly; sol-gel; Ormosil; corrosion protection; hybrid coating; multilayer stratification; nanostructured materials; nanotechnology; nanostructured thin films.
International Journal of Nanotechnology, 2004 Vol.1 No.3, pp.347 - 365
Published online: 19 Jul 2004 *Full-text access for editors Access for subscribers Purchase this article Comment on this article