Stabilization of verdigris pigment on paper : evaluation of antioxidants under mild accelerated degradation conditions

Malešič, Jasna (avtor), Retko, Klara (avtor), Finšgar, Matjaž (avtor), Kralj Cigić, Irena (avtor)

Copper-based pigments, such as verdigris, have caused severe damage to many important historical documents, and their preservation remains a significant concern for paper conservators and researchers. This study re-evaluates the efficacy of two promising antioxidants, tetrabutylammonium bromide (TBABr) and benzotriazole (BTA), as stabilization agents for paper documents containing verdigris pigment. The evaluation was conducted under mild accelerated degradation conditions using historically accurate mock-up paper samples. To assess the stability of the mock-up papers, various parameters were measured during accelerated degradation, including colour, molecular weight (Mw), and pH value. Size exclusion chromatography measurements of Mw confirmed that TBABr provided superior stabilization compared to BTA. Additionally, the total colour change was slightly more pronounced in the samples treated with BTA compared to those treated with TBABr. However, during degradation, some paper samples containing thicker application of pigment exhibited significant black and brown spots, regardless of treatment (untreated, treated with BTA, or TBABr). X-ray photoelectron spectroscopy confirmed the presence of both Cu(I) and Cu(II) oxidation states in all samples, with a higher Cu(II) content on the surface of TBABr treated samples compared to those treated with BTA. This may indicate differences in the mechanisms of degradation. Raman spectroscopy identified the spots on both untreated and TBABr-treated samples as copper(II) oxide.

• Jezik: Angleški jezik
• Ključne besede: verdigris, degradation, paper, stabilization, antioxidants
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FKKT - Fakulteta za kemijo in kemijsko tehnologijo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2025
• Št. strani: 12 str.
• Številčenje: Vol. 90, iss. 5, art. e202400670
• PID: 20.500.12556/RUL-168919
• UDK: 7.025.3/.4:691.14
• ISSN pri članku: 2192-6506
• DOI: 10.1002/cplu.202400670
• COBISS.SI-ID: 226885635
• Datum objave v RUL: 28.05.2025

Gradivo je del revije

• Naslov: ChemPlusChem
• Skrajšan naslov: ChemPlusChem
• Založnik: Wiley, Chemistry Europe
• ISSN: 2192-6506
• COBISS.SI-ID: 2732539

Licence

• Licenca: CC BY-NC-ND 4.0, Creative Commons Priznanje avtorstva-Nekomercialno-Brez predelav 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by-nc-nd/4.0/deed.sl
• Opis: Najbolj omejujoča licenca Creative Commons. Uporabniki lahko prenesejo in delijo delo v nekomercialne namene in ga ne smejo uporabiti za nobene druge namene.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: verdigris, papir, razgradnja, stabilizacija, antioksidanti, ohranjanje dokumentov