Calcium Phytate in the Treatment of Corrosion Caused by Iron Gall Inks: Effects on Paper
| Main Authors: | , , |
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| Format: | Article |
| Language: | English German French |
| ISSN: | 0034-5806 |
| Online Access: | http://www.viks.sk/chk/res_1_05_44_62.doc |
| Abstract: | SUMMARY. Iron gall ink, widely used in the past, is a significant factor in the deterioration of documents and books conserved in libraries and archives. Numerous studies have been conducted in the past to determine the mechanism of the formation of the ink and its corrosive action on paper, however it has only been recently that it has been possible to understand the chemical mechanisms at the root of these processes. It seems certain that the excess Fe ions in the ink act as catalysts in the oxidation degradation reactions of cellulose. The use of phytic acid salts seems to be one of the more interesting systems adapted to combating this phenomenon, having the positive attribute of "chelating" the Fe2+ and impeding it from catalysing the oxidation reactions. The scope of the work reported in this article was to evaluate the effects of the treatment on paper supports. A combined treatment with both calcium phytate and calcium carbonate seems particularly promising CONCLUSION. Following the treatments and ageing, the uninked samples did not show significant changes in pH, alkaline reserve or whiteness. Folding endurance and tensile strength did not change notably after neither the phytate-carbonate combined, nor the carbonate treatment, nor after artificial ageing. Degree of polymerization decreased by approximately 10% in the untreated samples after artificial ageing, while it remained constant in the treated ones. In the inked samples, the pH values were higher after treatment and remained higher than in the untreated ones, even after ageing. DP remained constant after the treatments. Ageing resulted in a notable decrease (approximately 40%) of the untreated samples, but this effect was much less in the samples treated with carbonate: 23% and almost unnoticeable in the sample given the combined phytate-carbonate: 10%. These results clearly confirm that calcium phytate is effective in inhibiting the acid corrosion of paper by iron gall inks and they demonstrate that the treatment is innocuous to the paper support |
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| ISSN: | 0034-5806 |
