Influence of SDBS on Dispersive Stability of Al₂O₃ Nano-Suspenions

In this paper, the influence of sodium dodecylbenzenesulfonate (SDBS) on the dispersive behavior of Al₂O₃ nanoparticles in water are investigated by measuring zeta potential and hydrodynamic sizes of the nanoparticles in suspension at different pHs and different concentration of SDBS. The experimental results show that at different pHs the magnitude of zeta potential has very homologous relation with particle size, the higher magnitude of zeta potential values are, the smaller of the hydrodynamic sizes are, and the better dispersive stability of the nano-suspension is, and that an optimizing pH value of the nano-suspension can induce the highest magnitude zeta potential, then result in the best dispersion stability of the nano-suspension. It is also found that concentrations of SDBS can significantly affect the values of zeta potential and hydrodynamic sizes of the nanoparticles by electrostatic repulsions. Similarity, optimizing concentrations of SDBS can also lead to the highest enhancement of the dispersive stability of the Al₂O₃ suspension and the optimizing concentration for SDBS is 0.09% in 0.1% Al₂O₃ nano-suspensions, which have the best disperse results.