Adsorption of acrylic copolymers at the alumina–water interface

The adsorption and electrokinetic characteristics of alumina suspensions in the presence of an acrylic acid/acrylic ester copolymer as a dispersant have been studied. The adsorption isotherms are of Langmuirian type. The conformation of adsorbed copolymers on alumina in acidic and basic regions is discussed based on the adsorption density results. The adsorption and sedimentation results reveal that the optimum dosage of copolymer is 2.0 dmb% (dry mass base) of Al2O3. FTIR analysis is employed to probe the possible adsorption mechanism. Large differences exist between the sediment morphology resulting from the suspensions without and with dispersants. The sediment morphology is found to exhibit self-similar characteristics. Moreover, the fractal dimension values of sediments when different amounts of dispersants were added are calculated and compared.