A 3-mercapto-propyl-trimethoxysilane coating (PropS-SH) applied on Cu-Si-Mn bronze, patinated by “liver of sulphur” was investigated as a non-toxic alternative to Incralac®, usually applied on outdoor artistic bronzes. Electrochemical testing was performed in synthetic acid rain. Exposure to temperature/UV cycles and accelerated corrosion test simulating unsheltered exposure to rainwater was also carried out. The exposed samples were characterised by FEG-SEM coupled with EDS on FIB cross-sections and XPS on free surfaces. The black patina without protective coating was scarcely protective against bronze corrosion and easily transformed into cuprous oxide. PropS-SH coating fully preserved the black patina microstructure and phase constituents (cuprous oxide and cuprous sulphide). The PropS-SH coating also resulted more protective than Incralac® when aged under run-off conditions. Selective dissolution of copper from the silicon bronze alloy was observed on both uncoated and Incralac®-coated bronze, leading to the formation of an internal Si-rich corrosion layer.

Evaluation of the protectiveness of an organosilane coating on patinated Cu-Si-Mn bronze for contemporary art

C. Chiavari;C. Martini;C. Monticelli;F. Zanotto;A. Balbo;
2019

Abstract

A 3-mercapto-propyl-trimethoxysilane coating (PropS-SH) applied on Cu-Si-Mn bronze, patinated by “liver of sulphur” was investigated as a non-toxic alternative to Incralac®, usually applied on outdoor artistic bronzes. Electrochemical testing was performed in synthetic acid rain. Exposure to temperature/UV cycles and accelerated corrosion test simulating unsheltered exposure to rainwater was also carried out. The exposed samples were characterised by FEG-SEM coupled with EDS on FIB cross-sections and XPS on free surfaces. The black patina without protective coating was scarcely protective against bronze corrosion and easily transformed into cuprous oxide. PropS-SH coating fully preserved the black patina microstructure and phase constituents (cuprous oxide and cuprous sulphide). The PropS-SH coating also resulted more protective than Incralac® when aged under run-off conditions. Selective dissolution of copper from the silicon bronze alloy was observed on both uncoated and Incralac®-coated bronze, leading to the formation of an internal Si-rich corrosion layer.
2019
Masi, G.; Josse, C.; Esvan, J.; Chiavari, C.; Bernardi, E.; Martini, C.; Bignozzi, M. C.; Monticelli, C.; Zanotto, F.; Balbo, A.; Svara Fabjan, E.; Kosec, T.; Robbiola, L.
File in questo prodotto:
File Dimensione Formato  
Masi Evaluation of the protectiveness of an organosilane coating on patinated Cu-Si-Mn bronze for contemporary art.pdf

solo gestori archivio

Descrizione: Articolo completo
Tipologia: Full text (versione editoriale)
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 5.72 MB
Formato Adobe PDF
5.72 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Masi_24535.pdf

accesso aperto

Tipologia: Pre-print
Licenza: Creative commons
Dimensione 5.82 MB
Formato Adobe PDF
5.82 MB Adobe PDF Visualizza/Apri

I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/2395994
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 28
  • ???jsp.display-item.citation.isi??? 27
social impact