Coexistence effect of colloidal silica on the radiation induced reactions in aqueous solution

Kumagai, Yuta   ; Nagaishi, Ryuji ; Yamada, Reiji; Muroya, Yusa*; Katsumura, Yosuke

Coexistence effect of colloidal silica on the radiation-induced reactions was studied by - and pulse radiolysis technique. First, reduction yields of metal ions in acidic aqueous solutions of colloidal silica were measured by radiolysis experiment. The yields slightly decrease with increasing amount of colloidal silica. From this result, primary yields of reactive species are unlikely to increase by addition of silica. Then reactivity of colloidal silica toward products of water radiolysis was studied by pulse radiolysis experiment. In sodium bicarbonate solution, the yield of carbonate radical formed by reaction of OH radical with bicarbonate ion was measured to decrease in the presence of colloidal silica. This result indicates a competitive reaction between colloidal silica and bicarbonate ion with OH radical, and the reactivity of colloidal silica toward OH radical.