Protection of Patinated Bronze by Non-Toxic Inhibitors

Marušić, Katarina (2010) Protection of Patinated Bronze by Non-Toxic Inhibitors. Doctoral thesis, University of Zagreb.

Preview

PDF - Published Version - other Download (4MB) | Preview

Abstract

Bronze is often used for sculptures and building structures. These objects are often covered with patina, a layer of corrosion products, which confers their aesthetic and also protects the substrate bronze. Due to the increasing atmospheric pollution these layers are often dissolving when exposed in urban environment. This work proposes the use of innoxious imidazole compounds as corrosion inhibitors: 4-methyl-1-phenylimidazole (PMI), 4-methyl-1-p-tolylimidazole (TMI) and 1-H benzimidazole (BZI) on the Cu-6Sn (wt-%) bronze, in a diluted Na2SO4 + NaHCO3 solution simulating acid rain in urban environment. The results of the electrochemical investigations have shown that PMI protects the bronze without patina layer at pH3, but not at pH5. TMI and BZI protect this alloy in both media. On the Cu-6Sn bronze, three types of patinas were synthesized by a chemical, thermochemical and electrochemical method. The morphological and structural characterization of these patinas was performed by SEM, EDS and Raman spectroscopy. It was found that the chemical patina is composed essentially of brochantite, the thermochemical patina of atacamite, and the electrochemical patina of malachite. All three patinas have also a smooth part of surface consisting of cuprite. As corrosion inhibitor TMI was used on all patinas, in the Na2SO4 + NaHCO3 solution at pH 5. The results have shown that it improves the stability of the patinas. PMI and BZI were used on the electrochemical patina where BZI, unlike PMI showed good protective effect.

Item Type:	Thesis (Doctoral thesis)
Uncontrolled Keywords:	Adsorption isotherms; Copper-tin bronze patina; EDS; Electrochemical impedance spectroscopy; Imidazole corrosion inhibitors; Raman spectroscopy; SEM; Urban acid rain
Subjects:	NATURAL SCIENCES > Chemistry > Physical Chemistry TECHNICAL SCIENCES > Chemical Engineering TECHNICAL SCIENCES > Chemical Engineering > Chemical Engineering in Material Development
Divisions:	Division of Materials Chemistry
Depositing User:	Katarina Marušić
Date Deposited:	06 Jul 2023 10:13
URI:	http://fulir.irb.hr/id/eprint/8009

Actions (login required)

View Item