Effect of organic additives on the zeta potential of PLZST and rheological properties of PLZST slurries

In order to investigate the effect of organic additives on the zeta potential of PLZST (Pb0.97La0.02Zr0.66Sn0.25Ti0.09), the zeta potential of PLZST powder with addition of dispersant, binder, plasticizer were performed. The experimental results indicated that the zeta potentials of PLZST without any organic addition were tightly related to the titration sequence and their IEPs (isoelectric point) were also not constant. The zeta potentials of PLZST with organic additives were strongly dependent on the structure, polarity and weight of the added organic additives. The dispersant did not greatly reduce the zeta potential of PLZST due to its good polarity and ionization. Compared to the IEP of PLZST without dispersant addition, the IEP of PLZST with dispersant addition switched from 8.7 to 3.5. The zeta potential of PLZST with binder addition seriously decreased due to electrostatic screening. Since dispersant is a highly polar polyelectrolyte, the zeta potential of PLZST mixed with dispersant, binder and plasticizer addition was dominated by the dispersant. pH variation has great effect on the viscosity of PLZST slurries without organic addition; however, pH variation did not show an obvious influence on the viscosity of PLZST slurries with organic additives.