Protection of Copper Corrosion by an Ultrathin Two‐Dimensional Polymer Film of Alkanethiol Monolayer

Abstract

An ultrathin (ca. 5.6 nm thick), closely packed (self-assembly), tightly interconnected (two-dimensional polymer), and water-repellent (>1300 of the contact angle with water) film was prepared by modification of an 11-mercapto-1-undecanol self-assembled monolayer adsorbed on a copper surface with 1,2-bis(trichlorosilyl)ethane and subsequently with octade-cyltrichiorosilane at 5>< iO M for 24 h. This film prevented copper corrosion in aerated 0.5 M Na,S04 with the protec-tive efficiency, P of the film being maintained at over 95 % in the solution for 15 h. The film provided excellent protec-tion against indoor atmospheric corrosion of copper for 300 days. Effects of the surface roughness on the water repellence of the surface covered with the film and on the P value of an unmodified or modified alkanethiol monolayer were stud-ied by using atomic force microscopy to examine mechanically abraded and electropolished copper surfaces.