Effect of Pluronics and surfactant adsorption onto dolomite suspension zeta potential and stability

Abstract

Two kinds of Pluronics (PEO-PPO-PEO triblock copolymers) were used in these studies. They have mixed with anionic surfactant (sodium oleate). The adsorption isotherms of surfactant and copolymer-surfactant mixture onto dolomite have been determined. The adsorbed amount of the Pluronics increases with increasing concentration and reaches plateau. An increase of adsorbed amounts of anionic surfactant onto the mineral surfaces (dolomite) has been observed at the presence of Pluronic copolymers. The adsorption effect of triblock copolymers has been investigated on the zeta potential of dolomite at the water suspension. The interaction of anionic surfactant with copolymers causes a decrease of zeta potential to small amount due to the deformation of double electrical layer. The adsorbed non-ionic Pluronic layer partially screens the surface charge of mineral particles, and thus, reduces the zeta potential. On the other hand, the adsorption of anionic surfactant and copolymer caused a decrease of negative value of zeta potential both investigated minerals. The stability of dolomite suspension depends on the both copolymer and sodium oleate concentrations.