Determination of early warning signs for photocatalytic degradation of titanium white oil paints by means of surface analysis

Determination of early warning signs for photocatalytic degradation of titanium white oil paints by means of surface analysis

van Driel, B.A. (TU Delft (OLD) MSE-4; Rijksmuseum; Cultural Heritage Agency of the Netherlands)
Wezendonk, T.A. (TU Delft ChemE/Catalysis Engineering)
van den Berg, K. J. (Cultural Heritage Agency of the Netherlands)
Kooyman, P.J. (TU Delft ChemE/Catalysis Engineering)
Gascon, Jorge (TU Delft ChemE/Catalysis Engineering)
Dik, J. (TU Delft (OLD) MSE-4)

2017

Titanium white (TiO₂) has been widely used as a pigment in the 20th century. However, its most photocatalytic form (anatase) can cause severe degradation of the oil paint in which it is contained. UV light initiates TiO₂-photocatalyzed processes in the paint film, degrading the oil binder into volatile components resulting in chalking of the paint. This will eventually lead to severe changes in the appearance of a painting. To date, limited examples of degraded works of art containing titanium white are known due to the relatively short existence of the paintings in question and the slow progress of the degradation process. However, UV light will inevitably cause degradation of paint in works of art containing photocatalytic titanium white.In this work, a method to detect early warning signs of photocatalytic degradation of unvarnished oil paint is proposed, using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Consequently, a four-stage degradation model was developed through in-depth study of TiO₂-containing paint films in various stages of degradation. The XPS surface analysis proved very valuable for detecting early warning signs of paint degradation, whereas the AFM results provide additional confirmation and are in good agreement with bulk gloss reduction.

Atomic force microscopy
Degradation
Oil paint
Photocatalysis
Titanium dioxide white
X-ray photoelectron spectroscopy

http://resolver.tudelft.nl/uuid:8290cac7-9662-4235-9be9-397dc5667156

https://doi.org/10.1016/j.saa.2016.04.026

2019-02-01

1386-1425

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 172, 100-108

Accepted Author Manuscript

Institutional Repository

journal article

© 2017 B.A. van Driel, T.A. Wezendonk, K. J. van den Berg, P.J. Kooyman, Jorge Gascon, J. Dik