The Use of Halides for Stabilisation of Iron-Gall Ink Containing Paper - The Pronounced Effect of Cation

It has long been known that transitional metal ions and acids in iron gall inks induce degradation of paper support, thus endangering numerous historical materials. Stabilization treatment should therefore consist of deacidification and addition of antioxidants that could be used for stabilization of all historical material, regardless to their iron gall ink composition. This contribution discusses the effects of various quaternary ammonium and phosphonium halides on iron gall ink corrosion of cellulose in alkaline environment. It is demonstrated that the size of the cation affects the extent of stabilization obtained with various quaternary ammonium bromides, with the strongest stabilization achieved with tetrabutylammonium chloride, bromide and dodecyltrimethylammonium bromide. An addition of either tetrabutylammonium bromide or chloride did not adversely affect the brightness of paper during accelerated ageing.