Adsorption of water on oxidized surface of metals

Effect of a diphilic corrosion inhibitor on the iron passivity in oil-field electrolytes

“…In this case, the inhibitor remains effective until its protective film has completely or partially desorbed from the metal surface [1,2,5,6].…”

“…Firm adsorption (in the ideal case, chemisorption) at a metal surface is only a necessary but not sufficient condition for corrosion inhibition. A sufficient condition for high protective effects is the formation of a specific surface layer (so-called structuralmechanical barrier) composed of a considerable number (about 10 for the inhibitor IKB-4) [6] of oriented and time-arranged micellar structures. This layer prevents the metal surface from contacting the corrosive medium for a long period of time, which ensures a rather high protective effect and favors oxide-free passivation of the metal surface and the protective aftereffect of inhibitors of this class.…”

“…Protective films of diphilic corrosion inhibitors were studied with our participation at the Institute of Physical Chemistry, Russian Academy of Sciences, by radiofrequency microweighing (with a piezoelectric quartz resonator) and the method of contact potential difference [6]. Those investigations confirmed both the multilayer adsorption of the inhibitor' molecules and the regular alternation of molecular orientations from layer to layer so that any two adjacent layers are in contact through either their polar or nonpolar fragments.…”

“…In effective inhibitors, including the compound under consideration, there is a favorable colloid balance between polar groups and hydrophobic radicals (so-called hydrophilic-lipophilic balance [3]). It is known [1,2,6,8] that the protective effects of organic amines are substantially enhanced in the presence of hydrogen sulfide. This was confirmed by the practical application of the inhibitor IKB-4.…”