Nanoparticle de-acidification of the Mary Rose

The preservation of waterlogged archaeological wooden finds, such as Henry VIII's flagship the Mary Rose1–3, is complicated by the biological, chemical, and mechanical changes induced from prolonged exposure to a marine environment. Of particular concern are sulfur species that form acidic compounds that attack wood4. Here we show that different sulfur compounds do not form acids at the same rate or pathway and propose a preservation strategy of applying SrCO3 nanoparticles. These nanoparticles not only neutralize problematic sulfuric acid, but also reduced sulfur compounds, such as sulfur and pyrite, which pose a long term threat. This is the first treatment that eliminates acidification at the root. Although this strategy was devised for the Mary Rose, it could be employed to preserve any archaeological organic artifact rich in problematic sulfur, from sunken ships5,6 and silk tapestries7 to ancient texts8 and parchments9.