Zeta potential measurement on lithium lanthanum titanate nanoceramics

Abstract The zeta potential, isoelectric point, and agglomeration of Li 0.5 La 0.5 TiO 3 (LLTO) nanoparticles dispersed in aqueous media at different ionic strengths have been studied. The zeta potential was determined from electrophoretic mobility measurements, according to Smoluchowski's equation, for Li 0.5 La 0.5 TiO 3 suspensions in NaCl and KCl electrolytes with ionic strengths of 1, 10, and 100 mmol/dm 3 . The isoelectric point (IEP), zeta potential ( ζ ), and the agglomeration were shown to strongly depend on the ionic strength of the Li 0.5 La 0.5 TiO 3 aqueous colloidal suspension in both NaCl and KCl electrolytes, which allows the determination of the effects of environmental conditions for Li 0.5 La 0.5 TiO 3 manipulation in aqueous colloidal systems. The suspensions of Li 0.5 La 0.5 TiO 3 nanoparticles reach the IEP in the pH range of 3–5. The ζ of Li 0.5 La 0.5 TiO 3 nanoparticles varied from positive to negative values with a pH increase, which allows for the control of the surface charge depending on the purpose. The pH range of 7–8 and an ionic strength ≤1 mmol/dm 3 are recommended as the most suitable conditions for both the LLTO colloidal shaping techniques application and the LLTO-based nanocomposite formation.