McQueen Caitlin M A, Tamburini Diego, Braovac Susan
Museum of Cultural History, University of Oslo, Postboks 6762 St. Olavs plass, 0130, Oslo, Norway.
Department of Chemistry and Industrial Chemistry, University of Pisa, via Moruzzi 13, I-56124, Pisa, Italy.
Sci Rep. 2018 Feb 13;8(1):2901. doi: 10.1038/s41598-018-21314-z.
Alum-treated wooden artefacts from the Oseberg collection display a great deal of morphological, structural and compositional inhomogeneity. Thus, an in-depth understanding of chemical processes underlying their degradation requires consideration of a variety of local environments. In addition to alum, sources of inorganic compounds include metal parts, corrosion products of which can migrate into the surrounding wood. In order to characterise the inorganic compounds a range of local environments, samples from several locations in a selection of composite objects have been investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDS). We have found that corrosion of iron rods used in reconstruction has formed iron(II) sulfates, which have migrated into the alum-treated wood to form sulfates containing combinations of potassium, aluminium, iron(II) and iron(III) cations. Reactions of alum were also evident from the presence of alunite in some samples. Areas with significant abundances of zinc sulfates, zinc sulfide and elemental sulfur were also detected. These results provide a first-time window into the complex array of inorganic species that can be present in such composite alum-treated objects.
来自奥斯伯格藏品的明矾处理过的木制文物呈现出大量的形态、结构和成分不均匀性。因此，要深入了解其降解背后的化学过程，需要考虑多种局部环境。除了明矾，无机化合物的来源还包括金属部件，其腐蚀产物会迁移到周围的木材中。为了表征一系列局部环境中的无机化合物，我们通过X射线衍射（XRD）、傅里叶变换红外（FTIR）光谱、拉曼光谱和扫描电子显微镜（SEM）-能量色散X射线光谱（EDS）对一系列复合物体中几个位置的样本进行了研究。我们发现，重建过程中使用的铁棒腐蚀形成了硫酸亚铁，这些硫酸亚铁迁移到明矾处理过的木材中，形成了含有钾、铝、亚铁和铁（III）阳离子组合的硫酸盐。一些样品中明矾石的存在也表明了明矾的反应。还检测到了大量硫酸锌、硫化锌和元素硫的区域。这些结果首次为这类经明矾处理的复合物体中可能存在的复杂无机物种阵列提供了一个窗口。
