MeV SIMS - a tool to study modern paint materials and their stability

(1) Institute of Science and Tecnology in Art, Academy of Fine Arts, Schillerplatz 3, A-1010  Vienna, Austria
(2) Laboratory for Ion Beam Interactions, Rudjer Boskovic Institute, Bijenicka 54, HR-10000 Zagreb, Croatia
(3) Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/161, A‐1060 Vienna, Austria

Development of the modern industry in the 20th century caused production of a large variety of synthetic organic materials (binders and pigments) that have been used extensively by modern and contemporary artists. Degradation mechanisms and aging of those materials are typically studied with methods that can provide some information on the molecular structure like Gas Chromatography Mass Spectrometry (GC/MS), Pyrolysis-GC/MS, FTIR or Raman spectroscopy, Atomic Force Microscopy (AFM), and Nuclear Magnetic Resonance (NMR). In the present work for the first time, potential of the Secondary Ion Mass Spectrometry (SIMS) technique with MeV heavy ion excitation was explored for identification of synthetic organic materials used for paints materials. Self-made paint mock-up samples were prepared by mixing different pigment powders with alkyd and acrylic binders on glass slides as well as some commercially available paint formulas. Additionally, the mock-ups were artificially aged using enhanced outdoor conditions of UV radiation. Three sets of samples were analysed using MeV SIMS setup at the heavy ion microprobe in Zagreb: unaged, aged for two (UV1) and four months (UV2). As a primary ion beam focused 5 MeV Si4+ was used.  We will demonstrate that different synthetic organic pigments and binders can be easily identified by their molecular masses with MeV SIMS. Also, measurements have shown that it was possible to distinguishing among different blue phthalocyanines (PB 15:x) as well as between different binders (alkyd and/or acrylic) in the prepared mock-ups. At present, the potential of chemical imaging of aged paint surfaces compared to unaged ones is tested and first results will be reported.   

This work is supported by the Unity through Knowledge Fund (UKF) project: “Study of modern paint materials and their stability using MeV SIMS and other analytical techniques”.