34792
Accession Number
21198
Title Of Article Chaper
The characterization of patina components by x-ray diffraction and evolved gas analysis
Title Of Journal Book
Corrosion science
Volume
27
Issue
7
Pages
669-684
Collation
9 figs., 23 refs.
Publisher
Pergamon Press
Publisher City
Oxford
ISSN
0010-938X
Language Of Text
English
Literature Type
Serial
Literature Level
Analytic
Abstract
Fourteen patinated copper specimens, seven each from the Statue of Liberty, New York Harbor, and from roofs at AT&T Bell Laboratories in Murray Hill, NJ, ranged in atmospheric exposure from 1 to 100 years. X-ray diffraction showed the presence of cuprite, Cu<sub>2</sub>O, and brochantite, Cu<sub>4</sub>(SO<sub>4</sub>)(OH)<sub>6</sub>, in all specimens, and antlerite, Cu<sub>3</sub>(SO<sub>4</sub>)(OH)<sub>4</sub> (up to 0.7 times brochantite), atacamite, Cu<sub>2</sub>Cl(OH)<sub>3</sub> (up to 1.6 times brochantite), and/or posnjakite, Cu<sub>4</sub>(SO<sub>4</sub>)(OH)<sub>6</sub>.2H<sub>2</sub>O (up to 5.2 times brochantite) in some. Posnjakite has been previously reported as a patina component only once during short term exposures in Eurasia. It appears to be an early corrosion product which subsequently converts to brochantite. Mass spectrographic examination of gases emitted from heated patinas provides further information on patina composition, in particular on the presence of both carbonate and oxalate in widely varying ratios. -- AATA
Keywords
Copper;patina;Analysis;Identification;X-ray diffraction; Brochantite; Antlerite;Atacomite;Posnjakite AATA
pub_id
34792