ИСТИНА

Corrosion, electrochemical and physicochemical methods is applied to study the features of the adsorption and passivating effect of sodium decyl- and dodecylphosphonate (С10PNa and С12PNa) on zinc in borate buffer with pH 7,4. С10PNa and С12PNa form a passive film on zinc, increasing its stability in a humid atmosphere and preventing local depassivation with chloride ions in a neutral solution. The passivating effect of С12PNa is most pronounced on an oxide-free zinc surface and enhances with an increase in their concentration and duration of passivation. Strong adsorption of С10PNa and С12PNa on the reduced zinc surface, which can be described by the Temkin equation with a high value of the free adsorption energy was shown. Protective layer formed on zinc in С12PNa solution consists of the [С12PZn] complex with a ratio of ligand to complexing cation ≥ 1 : 1, ZnO and Zn(OH)2.