What are the characteristics of adsorption membrane-type corrosion inhibitors?

Adsorbent film-type corrosion inhibitors are all organic compounds containing N, P, S, O, etc. They are able to provide corrosion inhibition because their molecular structure contains hydrophilic groups that can adsorb onto the metal surface, as well as hydrophobic groups that cover the metal surface. In organic amines, the amino group is a hydrophilic group, while the hydrocarbon group is a hydrophobic group. The hydrophilic groups adsorb directionally on the metal surface, while the hydrophobic groups prevent water and dissolved oxygen from diffusing into the metal, thereby achieving a corrosion-inhibiting effect. When the metal surface is active and clean, adsorbed film-type corrosion inhibitors form a satisfactory adsorption film, providing excellent corrosion protection on the surface. However, if the metal surface is covered with corrosion products or scale deposits, it cannot provide suitable conditions for the formation of an adsorption model anti-corrosion film. Therefore, when using such corrosion inhibitors, wetting agents can be added to help them penetrate the metal surfaces covered in rust, thereby enhancing their corrosion-inhibiting effect. Such corrosion inhibitors are not used in circulating cooling systems.