Examination of the influence of vapour phase inhibitors on the wettability of the iron surface by contact angle measurements

The influence of dicyclohexyl ammonium nitrite (DICHAN) and dicyclohexylamine (DICHAMIN) on the interfacial‐energetic behaviour of the real iron surface was estimated by means of approximation equations by the evaluation of contact angle measurements (advancing angle) on system of primary‐oxidecovered iron/liquid/gas. The presented results support the statement having be made already from ellipsometric investigations that the hydrophobicity of the iron surface during the initial phase of the contact with DICHAN is caused by its adsorption, whereas in the case of DICHAMIN it is brought about probably by protolytic interactions with the surface hydroxyl groups of the primary oxide layer of iron and contributes to the stabilization of the passive state, too.