We investigated the characteristics of heterogeneous layers composed of linear hydrolyzed polyvinylamine and branched polyethylenemine adsorbed at silica/water interfaces. The studies also included heterogeneous layers ethyleneirnine modified by grafting with C-12-C-(22) alkyl chains. Surface area exclusion chromatography was used to determine the interfacial relaxation and Surface affinity of the polyrner molecules within honlogeneous layers. The relaxation of bare and grafted polyethyleneimine was found to be small and of equal extent but to develop at different rates. Comparatively, the relaxation of hydrolyzed polyvinylamine was faster and of greater extent. Within heterogeneous layers cornposed of polyvinylarnine and bare or grafted polyethylenemine. the relaxation of the different molecules was strongly increased as compared to that prevailing in homogeneous layers. The chromatographic method was then used to determine the mode of layer establishment. The polymer coating profiles oil Successive glass fiber filters were found to depend oil the sequence of injection of the two polymers, due to the interfacial stability or instability of the initially established layer. It was shown that a previously established extremely thin layer of bare or grafted polyethyleneimine molecules strongly modified the adsorption profile of subsequently adsorbed polyvinylamine molecules. (c) 2005 Elsevier Inc. All rights reserved.