Strontium carbonate nanoparticles for the surface treatment of problematic sulfur and iron in waterlogged archaeological wood

Stabilising waterlogged archaeological wooden artefacts for display presents a challenge for conservators and scientists. Sulfur compounds, incorporated into the wood prior to excavation, can lead to acid formation when exposed to oxygen, and in the presence of iron ions. Strontium carbonate nanoparticles have recently been shown to reduce the production of acid formation at the root by reacting with inorganic sulfur-containing compounds. Here, we show the feasibility of using this treatment on small samples where consolidating treatments have already been performed. It is found that PEG 200 does not prevent the reactivity of the nanoparticles with the sulfur compounds present in the artefacts. A surface brushing application method was found to be successful whilst retaining the visual integrity. In addition, it was found that this technique results in the leaching of iron from the surface layers, preventing future build up of acid catalysed by iron compounds.