Microchemistry and Microscopy Art Diagnostic Laboratory, University of Bologna, 40126 Ravenna, Bologna, Italy.
Anal Bioanal Chem. 2011 Mar;399(9):2899-907. doi: 10.1007/s00216-010-4279-2. Epub 2010 Oct 15.
In the literature, the ability to transform metal compounds into metal oxalates has been reported for different species of fungi. This could be an innovative conservation method for archaeological and artistic metal artefacts. In fact, with a high degree of insolubility and chemical stability even in acid atmospheres (pH 3), metal oxalates provide the surface with good protection. Within the framework of the EU-ARTECH project, different fungal strains have been used to transform existing corrosion patinas on outdoor bronze monuments into copper oxalates, while preserving the physical appearance of these artefacts. Given the promising results obtained with this first attempt, the same approach is now applied within the BAHAMAS (Marie Curie Intra European Fellowship action) project, but extended to other metal substrates, for example iron and silver, which are frequently found in cultural heritage artworks and also encounter several problems of active corrosion. The research is investigating the formation mechanisms and adhesion properties of the newly formed metal oxalates by means of complementary analytical techniques (X-ray diffraction (XRD), FTIR microscopy, Raman microscopy, scanning electron microscopy (SEM-EDS), electrochemical impedance spectroscopy (EIS), colorimetry). For each metal substrate, the most appropriate fungal strain is going to be identified and applied to corroded sheets and the novel fungal treatment compared with those used so far. Treated metal sheets will be monitored during 1-year exposure to different cycles of artificial ageing, to evaluate the corrosion resistance of the fungal patinas obtained. The objective of this contribution is to present the first results achieved so far on naturally corroded bronze sheets during the EU-ARTECH project and the analytical procedure used for the testing of the proposed treatment performances during the BAHAMAS project.
在文献中，已经报道了不同真菌物种将金属化合物转化为草酸盐的能力。这可能是一种创新的考古和艺术金属文物保护方法。事实上，草酸盐具有高不溶性和化学稳定性，即使在酸性气氛（pH3）中也是如此，为表面提供了良好的保护。在欧盟-ARTECH 项目的框架内，已经使用不同的真菌菌株将户外青铜纪念碑上现有的腐蚀铜绿转化为草酸铜，同时保留这些文物的物理外观。鉴于首次尝试取得的有希望的结果，现在在 BAHAMAS（玛丽·居里欧洲内部奖学金行动）项目中，同样的方法被应用于其他金属基底，例如铁和银，这些金属基底经常出现在文化遗产艺术品中，也遇到了一些活跃腐蚀的问题。研究正在通过补充分析技术（X 射线衍射（XRD）、FTIR 显微镜、拉曼显微镜、扫描电子显微镜（SEM-EDS）、电化学阻抗谱（EIS）、比色法）研究新形成的金属草酸盐的形成机制和附着力特性。对于每种金属基底，将确定最合适的真菌菌株，并将其应用于腐蚀的薄片，并将新的真菌处理与迄今为止使用的处理进行比较。处理后的金属薄片将在 1 年的时间内受到不同人工老化周期的监测，以评估获得的真菌绿锈的耐腐蚀性。本研究的目的是介绍在欧盟-ARTECH 项目中对自然腐蚀的青铜片迄今取得的初步结果，以及在 BAHAMAS 项目中测试所提议的处理性能所使用的分析程序。
