ИСТИНА

The use of organic compounds capable of forming self-assembled monolayers on the surface is an actively developing direction in increasing the corrosion resistance of metals. Such corrosion inhibitors include alkylphosphonic acids and their salt, which due to the presence of a reactive phosphonic group and a hydrophobic alkyl in the molecules are strongly adsorbed on the surfaces of metals and their oxides. Mainly studies of the features of surface modification of metals with alkylphosphonic acids or alkylphosphonates for increasing their corrosion resistance were carried out mainly on steel, titanium and aluminum. There are very few such studies on zinc or zinc coatings. The effect of alkylphosphonic acids or alkylphosphonates can be enhanced by trialkoxysilanes. They are also capable of self-assembly on the surfaces of many metals that gives them anticorrosion, adhesive and hydrophobic or superhydrophobic properties. The possibility of increasing the protective properties of films formed on zinc in the presence of sodium dodecylphosphonate by trialkoxysilanes with various structures, including using the method of layer-by-layer passivation has been studied. The effect of conditions for obtaining coatings based on sodium dodecylphosphonate and trialkoxysilanes and the preliminary preparation of the zinc surface using laser treatment and subsequent heating has been estimated. The composition and structure of phosphonate-siloxane films formed both on a smooth and laser-textured zinc surface have been studied. It was shown that the corrosion protection efficiency of zinc in a chloride-containing solution and in a humid atmosphere is higher with a combination of sodium dodecylphosphonate and trialkoxysilanes than with the individual corrosion inhibitors. The optimal conditions for obtaining thin coatings on zinc in the presence of these corrosion inhibitors in terms of anticorrosive efficiency have been identified. It was found that upon layer-by-layer passivation by sodium dodecylphosphonate with trialkoxysilanes, the structure of the latter has a great influence on the protective properties of the films and the sequence of their formation. The most effective is layer-by-layer passivation of zinc with sodium dodecylphosphonate and n-octyltriethoxysilane with preliminary laser texturing of the surface, which allows one to obtain resistant coatings with high protective and hydrophobic properties both in a chloride-containing aqueous solution and in a humid atmosphere. Changing the morphology of the zinc surface by laser treatment and subsequent heating allows one to achieve its superhydrophobization upon the formation of phosphonate-siloxane coatings, increasing their protective properties and stability in atmospheric conditions.