Figure 5.

Osmotic compression experiments on colloidal (a) SM 30 (particle size a= 5 nm) (b) HS 40 (a=8 nm) and (c) TM 50 (a=14 nm) show how the osmotic pressure of the silica dispersions depends on their volume fraction, particle size and the salt concentration outside the dialysis sack. The solid lines give predictions from the Poisson–Boltzmann cell model (equation (2.14)), under corresponding conditions, assuming a bare surface charge density of σ=0.5 e nm⁻². Some data for HS 40 at 5 mM are incorporated from Li et al. [49]. All figure data are provided as the electronic supplementary material.