BLUE SILVER - TRANSFORMATION OF CLUSTERS AND METAL COAGULATION

The formation and transformations of ''blue silver'' (lambda(max) greater than or similar to 700 nm) during gamma-irradiation of a weakly alkaline (pH 9) aqueous solution containing AgClO4, polyacrylic acid (PAA), and isopropanol were studied. We believe that ''blue silver'' is a linear silver cluster stabilized on a polymeric molecule. During radiation-chemical reduction the cluster is transformed into new clusters (lambda(max) = 365 and 460 nm). When all of the Ag+ ions present in the solution have been reduced, clusters coalesce and a new phase, i.e., colloidal silver particles, forms. The mechanism of the radiation-chemical transformations is discussed.