ABSTRACT
Here, is the depletion layer thickness (assumed equal to the radius of gyration of the polymer, RG), H = r 2a is the surface-to-surface particle separation, V1
solvent chemical potentials for the polymer solution and the pure solvent. It appears that the assumption = RG is generally acceptable providing that the polymer solution is in the dilute concentration regime. At higher polymer concentrations, however, the value of is reduced according to the relationship (Vincent, 1990):
where b is the bulk polymer concentration, and the index m has values of 0.75 and 1.0 in athermal and theta solvents, respectively. Values of the critical overlap concentration can be determined approximately from the relationship overlap = 4/[], where [] is the intrinsic viscosity of the polymer in bulk solution, as defined by Tanford (1961).
