Surface Force Measurement of Alumina Surfaces: Effect of Polyelectrolyte on the Dispersiveness of Aqueous Alumina Suspension

摘要

Surface forces between α-alumina surfaces were measured in aqueous solutions by colloidal probe atomic force microscopy, to elucidate the effects of presence of three sodium polyacrylate (PANa) preparations with different molecular weights (1200, 6500, and 30000) on the electrostatic forces and steric forces. PANa30000 and 6500 formed the steric layer at the concentration higher than 10~(-5)M, and their layer thicknesses were independent of the molecular weight, while PANa1200 could not form such effective steric layer. On the other hand, electric double layer force decayed efficiently as increasing the PANa molecular weight.