Figure 7.

Dependence of the ζ-potential (a) and the hydrodynamic radius (b) for a suspension of liposomes DOPC:DODAB with a 70:30 compositional ratio as a function of the PSS added. Aggregation takes place between the vertical dashed lines. The dashed rectangle on the panel a represents the instability region where the zeta potential measurements are not reproducible. (c) ζ-potential dependence of the hydrodynamic radius for all the liposome suspensions studied. The Velegol–Thwar theory predicts that the systems are unstable in the region between the two continuous lines. The horizontal dashed line represents the so-called ideal stability region.