The Self Assembly of Superhydrophobic Copper Thiolate Films on Copper in Thiol Solutions

It is common to think of thiols as molecules that form self-assembled monolayers on gold or similar metals, they have also been used as corrosion inhibitors on copper and steel, but we show here that if the copper remains in thiol solution corrosion is accelerated and a thick layer of corrosion products with a very rough surface forms. The layer is superhydrophobic; repelling water so effectively that it rolls off leaving the surface completely dry. It is composed of a copper (I) thiolate complex and growth occurs quite rapidly under normal conditions. The film morphology depends upon the solvent and thiol used. The presence of organic amines in the solution alters the reaction leading to the formation of thinner layers by removing corrosion products into solution, allowing the removal of native oxide layers.