Salvaged in 1982, the Mary Rose provides an unprecedented insight into Tudor society and technology. Although the low oxygen environment underwater helped to preserve the wood, interactions with bacteria, sea-water salts and sulfur compounds have and can continue to damage and degrade the wood structure. Whilst buried under the seabed, hydrogen sulfide formed by sulfur reducing bacteria migrated into the wood. This reacted with iron ions, from corroded fixtures, to form iron sulfides. Stable in low-oxygen environments, sulfur rapidly oxidises in the presence of iron under atmospheric conditions to form destructive acid. A suitable conservation strategy, going beyond current methods where potential acid sources remain in the wood, must be determined to prevent these priceless artefacts from being destroyed. The major factors in completely avoiding acid production are (i) removal of free iron ions, preventing reaction with sulfur compounds and (ii) sequestration of sulfate ions, ensuring they pose no threat to the artefact.
Salvaged hull of the Mary Rose (image courtesy of the Mary Rose Trust).
Our project provides a unique solution for the conservation of waterlogged wooden artefacts through the use of smart multifunctional magnetic nanocomposites capable of treating the Mary Rose hull and her ~19,000 artefacts. We aim to target and remove harmful entities lodged inside wooden structures, compared to current strategies whereby harmful chemicals remain in the wood. By using magnetic nanoparticles, we should be able to direct the particles to desired areas inside the wood, thereby optimising the removal of harmful species. Also at the heart of our design is the importance of a safe and non-destructive administration procedure. For this reason, we are employing tuneable, controllable thermoresponsive polymers to easily apply and remove our magnetic vehicles.
We hope that our approach will completely eliminate the destructive species without any disruptive interference to the structures. This is the first time such an approach has been taken and could profoundly change future artefact treatment strategies. We hope to provide conservators with a state-of-the-art quantitative and restorative method for the safe and rapid treatment of artefacts. Subsequent, more complex nanocomposite agents will ultimately change approaches to artefact treatments and be used to conserve a full range of specimens, including paper, textiles and leather.
Dr Serena Corr
University of Glasgow
Co-investigators: Dr Eleanor Schofield (Mary Rose Trust) and Professor Rachel O’Reilly (University of Warwick)