Copper patinas formed in the atmosphere. ll. A Qualitative Assessment of Mechanisms.
01 January 1987
The complex chemical makeup of patinas formed on copper exposed to the atmosphere is summarized, as is the chemical content of atmospheric gases, particles, and water droplets. This information is used to determine mechanisms of interaction between the copper surface and atmospheric constituents and to construct a qualitative model for the development of the patinas. Among the aspects of patina development not previously well understood but explained as a consequence of this work are the following: (1) the atmospheric origins of the different constituents of copper patinas are identified; and (2) the relative abundances of the minerals that constitute the patinas are seen to be a consequence of the chemical constraints imposed on the system by chemical equilibria and by the concentrations of reactive species in rain and fog.