The adsorption of dipyridyl and its complex with zinc(II) on silica surfaces

✍ Scribed by N.N. Vlasova; N.K. Davidenko; V.I. Bogomaz; A.A. Chuiko

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 275 KB
• Volume: 104
• Category: Article
• ISSN: 0927-7757
• DOI: 10.1016/0927-7757(95)03220-8

✦ Synopsis

The adsorption of dipyridyl, zinc ions and Zn(dipy) 2+ complex from the aqueous solutions on nonporous highly dispersed silica was investigated as a function of concentration and pH. From the comparison of the adsorption data with the equilibria in solution, the most probable reactions occurring at the silica/water interface at different pH values were deduced. The formation constants of the surface complexes (~SiOH... dipy), (~SiOH... Hdipy +) and (~SiO---Hdipy +) were calculated. It was found that the adsorption of the complex Zn(dipy) 2+ was considerably enhanced compared to that of aquated Zn 2+ ions. It was determined that the Zn(dipy) 2+ complex interacts with either dissociated or un-dissociated silanol groups of silica with the formation, in both cases, of the surface ternary complex (~(SiO),Zn(dipy)) ~2-")+.