Mussels owe their sessile way of life in the turbulent intertidal zone to adaptive adjustments in the process and biochemistry of permanent attachment. These have understandably attracted scientific interest given that the attachment is rapid, versatile, tough and not subverted by the presence of water. The adhesive pads of mussel byssus contain at least six different proteins all of which possess the peculiar amino acid 3, 4-dihydroxyphenylalanine (DOPA) at concentrations ranging from 0.1 to 30 mol %. Studies of protein distribution in the plaque indicate that proteins with the highest levels of DOPA, such as mefp-3 (20 mol %) and mefp-5 (30 mol %), appear to predominate at or near the interface between the plaque and substratum. Although the presence of DOPA in proteins has traditionally been associated with cross-linking via chelate-mediated or covalent coupling, recent experiments with natural and synthetic DOPA-containing polypeptides suggest that cross-link formation is not the only fate for DOPA. Intact DOPA, particularly near the interface, may be essential for good chemisorption to polar surfaces. Uniformly high DOPA oxidation to cross-links leads to interfacial failure but high cohesive strength, while low DOPA oxidation results in better adhesion at the expense of cohesion. Defining the adaptations involved in balancing these two extremes is crucial to understanding marine adhesion.

Adhesion a la moule.

XPS study of Eu(III) coordination compounds: Core levels binding energies in solid mixed-oxo-compounds EumXxOy

Characterization of surface film formed on titanium in electrolyte using XPS

The change in potential during repassivation of titanium in artificial bioliquids was examined, and the regenerated surface oxide film on titanium was characterized using X-ray photoelectron spectroscopy and Auger electron spectroscopy to elucidate the repassivation reaction of titanium in a biological system. The repassivation rate in Hanks' solution was slower than that in saline and was not influenced by the pH of the solution. This indicates that more titanium ions dissolve in a biological system than hitherto was predicted when the surface film is destroyed. Phosphate ions are taken up preferentially in the surface film during regeneration, and the film consists of titanium oxide and titanium oxyhydroxide containing titanium phosphate. Calcium ions and phosphate ions are adsorbed by the film after regeneration, and calcium phosphate or calcium titanium phosphate is formed at the outermost surface. Ions constituting Hanks' solution other than calcium and phosphate were absent from the surface oxide.

Repassivation of titanium and surface oxide film regenerated in simulated bioliquid

Photostabilization of coatings. Mechanisms and performance

The application of x-ray photo-electron spectroscopy to a study of interfacial composition in corrosion-induced paint de-adhesion

Assessment of photooxidation in multi-layer coating systems by time-of-flight secondary ion mass spectrometry

The interfacial chemistry of a conventional epoxy/dicyandiamide adhesive formulation applied to cold-rolled and galvanized steels has been studied by X-ray photoelectron spectroscopy (XPS). In both cases, the interfacial corrosion process appears to be dominated by attack on the metal substrate, and is reminiscent of crevice corrosion phenomena. On cold-rolled steel, analysis of the interfacial bond failure surfaces suggests that the contamination layer initially present on the substrate is not disturbed during bond formation. Bond failure appears to occur between the substrate and the contamination layer; the contamination layer remains largely intact on the interfacial surface of the adhesive after bond failure. On galvanized steel, the locus of failure appears to be at the adhesive-adherend interface, within a layer of zinc corrosion products. The contamination layer appears to have been partially displaced by the adhesive during bonding.

Interfacial chemistry of corrosion-induced bond degradation for epoxy/dicyandiamide adhesive bonded to cold-rolled and galvanized steels

—The interfacial reactions of galvanized steel with a poly(vinyl chloride) adhesive formulated with epoxy resin and dicyandiamide have been studied using X-ray photoelectron spectroscopy (XPS). The dicyandiamide was observed to segregate partially to the adhesive/substrate interface. A small amount of amine hydrochloride, evidently formed by reaction of dicyandiamide and HCI formed by dehydrochlorination of the poly(vinyl chloride), was observed near the adhesive/ galvanized steel interface. Dehydrochlorination of poly(vinyl chloride) appears to be enhanced in the adhesive/substrate interfacial region relative to the bulk, but less degradation was observed than for unmodified poly(vinyl chloride) formulations. In parallel studies on cold-rolled steel, neither thermal degradation nor amine hydrochloride formation was observed.

Interfacial chemistry of epoxy-modified poly (vinyl chloride) adhesive on cold-rolled and galvanized steels

Etude par spectrometrie photoelectronique RX des surfaces interfaciales generees par les pertes d'adherence sous l'effet de l'humidite pour divers types de revetements organiques appliques sur de l'acier

J. E. deVries

Papers

The application of x-ray photo-electron spectroscopy to a study of interfacial composition in corrosion-induced paint de-adhesion

Assessment of photooxidation in multi-layer coating systems by time-of-flight secondary ion mass spectrometry

Interfacial chemistry of corrosion-induced bond degradation for epoxy/dicyandiamide adhesive bonded to cold-rolled and galvanized steels

Interfacial chemistry of epoxy-modified poly (vinyl chloride) adhesive on cold-rolled and galvanized steels

Interfacial chemistry of humidity-induced adhesion loss