Interaction between ultrafine ceria particles and glycine

An ultrafine ceria powder of 15 nm equivalent spherical particle diameter was dispersed at 2 vol% solid in aqueous solutions with and without glycine (H2NCH2COOH) of 0.05-5.0 mass% against ceria. The addition of glycine increased the zeta potential of the ceria toward positive values in acidic suspensions. The phase separation of ceria suspensions due to the decreased repulsive energy with decreasing particle size, was suppressed by the steric stabilization effect of the adsorbed glycine. No significant influence of the glycine addition on the zeta potential and phase separation of the basic suspension was measured.