| AVS 61st International Symposium & Exhibition | |
| Conservation Studies of Heritage Materials Focus Topic | Thursday Sessions |
| Session CS-ThM |
| Session: | Conservation Studies of Heritage Materials |
| Presenter: | Karen Gaskell, University of Maryland, College Park |
| Authors: | K.J. Gaskell, University of Maryland, College Park A.A. Ponce, University of Maryland, College Park S. Gibbons, University of Maryland, College Park P. Zavalij, University of Maryland, College Park L. Brostoff, Library of Congress B. Eichhorn, University of Maryland, College Park |
| Correspondent: | Click to Email |
Iron gall inks were the major writing medium from the middle ages through the 19th Century in the Middle East and Europe, and are present in hundreds of thousands of important cultural heritage objects worldwide, including books, manuscripts and artistic drawings. Iron gall ink depending on its preparation is well known for its potentially corrosive effect on paper or other writing medium, over time, changes in temperature and humidity can accelerate this degradation resulting in the worst case, complete loss of documents. The major ingredients of ion gall ink are iron salts, most often iron sulfate, tannic acids derived from vegetable sources such as gall nuts and gum arabic used as a binder. In this study, X- Ray Photoelectron Spectroscopy (XPS), is used to probe the chemistry of iron gall ink and to study the effect of common preservation techniques such as deacidification and phytate treatment. Despite much research in this area the chemistry of iron gall ink is still poorly understood, including the structure of the complex itself, resulting from the reaction between iron sulfate and gallic acid. The two most widely accepted structures in literature have been proposed by Krekel and Wunderlich, these structures will be discussed and compared to XPS, Raman, FTIR and X-ray crystallography data obtained from model compounds.