Micro Raman Spectroscopy Investigation of Patinas Formed by Exposure of Copper to Vapor of Several Aqueous Electrolyte Solutions

Patina is a thin layer of corrosion, generally greenish-blue or brownish-green, naturally formed when copper or alloys of copper are exposed to the environment over time, making it an indication of its age and thus value. Artificial patinas can be formed by exposing copper to chemical compounds. Investigations on the formation and characteristics of artificial patinas can be used for the development of methods to create or restore the original aspect of natural patinas. In this work, the nature of the compounds formed in the artificial patina was investigated by Raman spectroscopy.