Figure 5.

The influence of anatase TiO2 primary particle size on dispersion zeta potential. Solution IS is 0.001 M. Inset shows the titania nanoparticle dispersion isoelectric point (IEP) as a function of primary particle size.

Suttiponparnit et al. Nanoscale Res Lett 2011 6:27   doi:10.1007/s11671-010-9772-1