Evaluation of Chemical Treatments on Verdigris-Contained Papers

• Main Authors: Chun-Kai Wang, 王俊凱
• Other Authors: Fei-Wen Tsai
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/77643345522882441831

碩士 === 國立臺南藝術大學 === 博物館學與古物維護研究所 === 104 === Verdigris has been widely used as a green pigment on the illustration of books, manuscripts, and maps from thirteenth to nineteenth centuries. However, the copper ion released by verdigris induces serious discoloration and brittleness of paper, which urgently call for a suitable conservation solution. In this study, the verdigris-induced paper degradation was simulated by artificial aging. Various paper properties were evaluated, such as discoloration, mechanical strengths, pH values, and degree of polymerization (DP). The functional groups of paper-based samples were monitored by Fourier Transform Infrared Spectroscopy (FTIR), and the pigment composition was analyzed by X-ray diffraction (XRD) and Raman spectroscopy. Several chemical reagents were evaluated, include tetra-n-butylammonium bromide (TBAB), ethylenediaminetetraacetic acid disodium salt (EDTA-2Na), benzotriazole (BTA), and calcium hydroxide. The result shows a serious discoloration on the verdigris-contained papers during the first few hours of accelerated aging. The discoloration was also shown on verdigris powder. After aging, the verdigris-contained papers showed lower mechanical strength and smaller DP than others. Furthermore, a carboxyl band of FTIR spectra at 1560 cm-1 was disappeared. Among the evaluated reagents, TBAB efficiently suppressed the discoloration of the verdigris-contained paper, while BTA changed its color immediately. Also, the sample treated with EDTA-2Na was serious weakened after aging, and the DPs of samples were improved by other reagents. The results made TBAB the most prominent among all the evaluated reagents.