Revealing the Distribution of Metal Carboxylates in Oil Paint from the Micro- to Nanoscale

Impact Factor:16.6

DOI number:10.1002/anie.201903553

Journal:Angewandte Chemie International Edition

Abstract:Oil paints comprise pigments, drying oils, and additives that together confer desirable properties, but can react to form metal carboxylates (soaps) that may damage artworks over time. To obtain information on soap formation and aggregation, we introduce a new tapping-mode measurement paradigm for the photothermal induced resonance (PTIR) technique that enables nanoscale IR spectroscopy and imaging on highly heterogenous and rough paint thin sections. PTIR is used in combination with μ-computed tomography and IR microscopy to determine the distribution of metal carboxylates in a 23-year old oil paint of known formulation. Results show that heterogeneous agglomerates of Al-stearate and a Zn-carboxylate complex with Zn-stearate nano-aggregates in proximity are distributed randomly in the paint. The gradients of zinc carboxylates are unrelated to the Al-stearate distribution. These measurements open a new chemically sensitive nanoscale observation window on the distribution of metal soaps that can bring insights for understanding soap formation in oil paint.

First Author:Xiao Ma

Co-author:Victoria Beltran,Georg Ramer,Georges Pavlidis,Dilworth Y. Parkinson,Mathieu Thoury,Tyler Meldrum,Andrea Centrone

Indexed by:Journal paper

Correspondence Author:Barbara H. Berrie

Volume:58,

Issue:34

Page Number:11652-11656

Translation or Not:no

Date of Publication:2019-06-21

Included Journals:SCI

Links to published journals:https://onlinelibrary.wiley.com/doi/10.1002/anie.201903553