A study is reported of the influence of organic acids (particularly acetic acid) on the development of lead patinas. Raman spectroscopy has been used to determine the chemical composition of patinas, while mass loss on descaling and scanning electron microscopy have followed their physical development. It was found that the mechanism of the patination process initially involved the formation of an oxide film which rapidly converted to a basic lead carbonate via normal and basic lead acetate intermediates. The high solubility of the acetate intermediaries influenced the morphology of the patina and increased the extent of its formation.
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