生物揭展剂在古书画文物揭展中的应用

揭展是书画重新装裱过程中最重要的一环。在装裱过程中所用的浆糊往往与画心、命纸很难分离,导致揭展过程复杂,且容易造成古书画的损毁。传统的水闷润揭展法对于难揭展的纸质画心极易揭晃。为解决这一问题,利用芽胞杆菌发酵产生的含有淀粉酶的胞外液制备生物揭展剂,并通过作用于宣纸老化材料验证了揭展效果。试验结果表明:枯草芽胞杆菌的发酵液去除菌体并透析后获得的生物揭展剂揭展效果较好。利用扫描电镜和拉力强度检测分析了生物揭展剂对书画文物的影响。结果表明:该生物揭展剂能够降低剥离力和纤维指数,与用水闷润相比,增加了宣纸样品在闷润后的抗拉强度,且对宣纸微观结构无明显影响;观察生物揭展后100天的样品并没有霉菌生成,表明该生物揭展剂具有很好的揭展安全性。在此基础上,对成套明代水陆画进行揭展,取得了良好效果。

Development of a biological method for removing ancient paintings and calligraphy from backings

Removal of paintings from old backings is the most critical step in the process of remounting the paintings. The paste used in the process of mounting often makes it hard to separate the painting itself from the support paper. As a consequence, the removal process is very complex and easy to result in damage of ancient paintings and calligraphy. In the traditional method of removal, the object is moistened with water for a long time in order to reduce the viscosity of the paste, and then a conservator use his/her fingers to gently twist the support paper, making possible removal of the old support paper and paste from the back of the painting. In the present study, the extracellular fluid of Bacillus fermentation was used to make a biological removal agent. The effectiveness of the agent on the aged cotton paper was tested. The results showed that the biological agent obtained by using the fermentation broth of Bacillus subtilis, after dialysis to eliminate bacteria, had good effectiveness. The safety of using a biological agent to remove paintings was tested by scanning electron microscopy and tensile strength analysis. It is found that the biological agent can reduce the peeling force and fiber index, increase the tensile strength of paper samples, compared to water moistening, and has no significant effect on the paper microstructure. The agent improves the safety of removing backing papers. Good results have been achieved on treating a complete set of Ming Dynasty land and water paintings.