Investigating the impact of cleaning treatments on polystyrene using SEM, AFM and ToF-SIMS

Abstract

Concerns about the stability of plastic artefacts are commonly expressed when discussing the conservation of modern materials. One of the factors affecting the degradation of plastics is the presence of soil, degradation products and other contaminants on the surface. Cleaning treatments for plastic artefacts may therefore increase their stability as well as improving their visual appearance. While past studies have shown that dry, aqueous and solvent cleaning can visibly damage a plastic surface, the chemical and physical changes occurring to the surface at the micro-scale have been largely unexplored. In this work time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been used in conjunction with atomic force microscopy (AFM) and scanning electron microscopy (SEM) to examine the effect of cleaning treatments on the surface of sheet polystyrene. Chemometric analysis of the ToF-SIMS data reveals the presence of surfactant residues and contamination from cleaning agents while physical damage in the form of scratching has been characterised using AFM and SEM. It is anticipated such work will assist in informing future conservation treatments for plastics.