Protective properties of superhydrophobic coatings on copper and steel obtained by electrochemical method

Abstract

Superhydrophobic coatings are obtained by cathodic deposition of copper or nickel on a copper plate with treatment with an ethanol solution of highest carboxylic acids with a long hydrocarbon radical simultaneously or sequentially. They are characterized by a contact angle of water wetting of the order of 155...160°.These coatings protect the copper substrate from corrosion in conditions of 100% humidity for 100...180 days, while maintaining the contact angle within 152…154°. There is no mass loss. The influence of the reversal of the current during electrolysis on the value of the contact angle of wetting is investigated. SEM images of superhydrophobic coatings are presented, indicating multilevel roughness. Superhydrophobic coating on carbon steel is obtained by cathodic deposition of nickel and subsequent surface treatment in an ethanol solution of myristic acid and annealing at 60° for two hours. The influence of the duration of electrolysis on the value of the contact angle of wetting is estimated. Its value is in the range of 151…154°. Exposure of a coated steel plate for 50 days in conditions of 100% humidity is characterized by the absence of weight loss and maintaining the contact angle up to 154°.