Journal
JOURNAL OF RAMAN SPECTROSCOPY
Volume 43, Issue 11, Pages 1617-1622Publisher
WILEY
DOI: 10.1002/jrs.4167
Keywords
artistic patina; statuary bronzes; reactivity; Micro-Raman spectroscopy; SEM-EDXS
Categories
Ask authors/readers for more resources
In order to contribute to the improvement of restoration and conservation sciences of metallic artefacts belonging to Cultural Heritage, a wide research has been started on the study of artificial (artistic) and natural (corrosion or alteration) patinas of copper-based alloys. Micro-Raman spectroscopy (mu RS) coupled with scanning electron microscopy (SEM) equipped with energy Dispersive X-Ray Spectroscopy (EDXS) were applied for the characterization of a number of patinas made on metallic substrate reproducing the typical copper-based alloys used for statuary. A non alloyed copper sheet has been also used to simulate the architectural cover typically used after a specific cold spray coating. To reach these goals, a number of patinas were experimentally produced in our laboratory using the torch technique and reactive solutions based on water as a solvent containing, respectively, copper nitrate, iron nitrate and potassium sulfide (liver of sulfur). The only exception is a sample reproducing the architectural cover of a recent building nearly completely covered with copper sheets coated with copper salts. All the produced patinas were aged in a salt spray chamber and then studied with mu RS, SEM and EDXS in order to understand their evolution between the two known terms and therefore the reactions involved in all patinas. mu RS allowed us to detect as main constituents of the artistic patinas, before and after ageing: copper oxides (Cuprite and Tenorite), copper nitrates (Rouaite and Gerhardtite), copper chlorides (Botallackite, Atacamite and Paratacamite), a copper sulfate (Posnjakite), iron oxides (Magnetite and Hematite) and an iron hydroxide (Limonite). Copyright (C) 2012 John Wiley & Sons, Ltd.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available