Validity of the high temperature approximation and influence of polydispersity on the phase separation in charged colloidal dispersions

A recent perturbation calculation predicting a ‘liquid-gas’ phase separation of charge-stabilized colloidal suspensions is tested against the thermodynamically self-consistent generalized mean spherical approximation. A comparison between the two calculations shows that the perturbation calculation predicts a reasonably accurate critical temperature, but overestimates the critical density. These critical parameters are moreover shown to be rather insensitive to moderate degrees of polydispersity.