Simple azo-dyes carrying phosphonic acid and arsonic acid substituents such as 4-(4'-hydroxyphenyl azo) phenylphosphonic acid ( 5) and 4-(4'-hydroxyphenylazo) phenylarsonic acid ( 6) bind more strongly to high surface area oxides such as aluminium trihydroxide and goethite than their carboxylic and sulfonic acid analogues and the phosphonate-functionalized dyes have been shown to have greater humidity fastness when printed onto commercial alumina-coated papers. Adsorption isotherm measurements provide evidence for the formation of ternary dye/cyclodextrin/ surface complexes. Dyes which form such ternary complexes show higher light fastness when printed onto alumina coated papers in an ink formulation containing alpha-cyclodextrin.
|Number of pages||9|
|Publication status||Published - 2006|