Effects of pH and Dispersant Concentration on Properties of Li_(1.075)Nb_(0.625)Ti_(0.45)O_3 Aqueous Suspension

摘要

The dispersion behavior of the solid solution Li1.075Nbo.625Tio.45O3 (LNT) in aqueous media was studied. Optimum dispersing conditions were investigated in terms of zeta potential, sedimentation, and rheology measurements. Zeta potential measurement showed that the isoelectric point (IEP) of the LNT particles was shifted from pH 3.7 to pH 2.6 after adsorption of PAA-NH4 and made the LNT surface more electronegative. Good agreement between zeta potential, sedimentation, and rheological test was found, which identified an optimum pH value of 10 and an optimum dispersant concentration of about 0.6 wt%. The green microstructures of the casting tapes bear a direct relationship to the state of dispersion of the slurries. The results showed that PAA-NH4 is a suitable dispersant for obtaining well-dispersed LNT slurries.