Institute for the Protection of Cultural Heritage of Slovenia, Restoration Centre, Poljanska 40, Ljubljana, Slovenia.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Feb;78(2):740-6. doi: 10.1016/j.saa.2010.12.006. Epub 2010 Dec 14.
The investigation and characterisation of historical objects can be an exacting piece of work because of the small quantity of material that can be investigated and the degradation of the material and its value, which sometimes demands only non-destructive methods. In this study, as one such method, Raman spectroscopy was used to investigate the cellulose fibres of painting canvases and linings. Historical samples of fabrics were taken from different paintings and their linings from different locations in Slovenia. Raman spectra were recorded on the fibres of these historical samples. Additionally, a database of the Raman spectra of modern cellulose fibres was created and compared with the literature data. Differences in the Raman spectra of different cellulose fibres were observed, and on this basis fibres of different types were discriminated. The recorded Raman spectra of historical samples were compared with the database spectra of modern cellulose fibres. Strong luminescence effects because of the changes caused by ageing, degradation products and surface contamination caused difficulties in interpreting the Raman spectra of historical fibres. The luminescence effects were partly overcome by prolonged exposition times and previous "signal quenching" with the laser. The Raman spectra of historical cotton showed no luminescence effects, and only slight differences to the reference spectra of modern cotton fibres appeared, whereas the Raman spectra of historical flax fibres were overwhelmed with luminescence and showed changes in spectra through degradation. The research showed that by using Raman spectroscopy the identification and differentiation of different cellulose fibres and materials that accompany cellulose in the fibres are possible and that degraded and aged material can be differentiated.
由于可用于研究的材料数量较少，以及材料及其价值的退化，对历史文物的调查和特征描述可能是一项艰巨的工作，这有时仅需要采用非破坏性的方法。在这项研究中，拉曼光谱被用作一种这样的方法，用于研究绘画画布和衬里的纤维素纤维。从不同的画作和不同地点的画框中采集了历史样本的织物。对这些历史样本的纤维进行了拉曼光谱记录。此外，还创建了一个现代纤维素纤维拉曼光谱数据库，并与文献数据进行了比较。观察到不同纤维素纤维的拉曼光谱存在差异，并在此基础上对不同类型的纤维进行了区分。将历史样本的记录拉曼光谱与现代纤维素纤维的数据库光谱进行了比较。由于老化、降解产物和表面污染引起的变化而产生的强烈荧光效应给拉曼光谱的解释带来了困难。通过延长曝光时间和先前用激光进行的“信号猝灭”，部分克服了荧光效应。历史棉的拉曼光谱没有荧光效应，仅与现代棉纤维的参考光谱略有差异，而历史亚麻纤维的拉曼光谱则被荧光淹没，并因降解而出现光谱变化。研究表明，通过使用拉曼光谱，可以识别和区分不同的纤维素纤维以及纤维中伴随纤维素的材料，并且可以区分降解和老化的材料。
