O. Mondainmonval et al., DEPLETION FORCES IN THE PRESENCE OF ELECTROSTATIC DOUBLE-LAYER REPULSION, Physical review letters, 75(18), 1995, pp. 3364-3367
We report direct measurements of the repulsive force-distance profiles
between submicronic colloidal droplets stabilized by an ionic surfact
ant in the presence of the same surfactant micelles. We establish that
the repulsive force profile may be described by a sum of two contribu
tions. One is repulsive and arises from the presence of the droplets'
double layers. The other originates in the depletion of charged micell
es and is attractive. We conclude that the electrostatic repulsion bet
ween the micelles and the droplets enhances the depletion force. This
effect is simply accounted for by considering an effective larger drop
let diameter. We present the empirical relation between this extra thi
ckness and the Debye length.