  The liquid-gas phase diagram for polydisperse dipolar hard-sphere fluid with
polydispersity in the hard-sphere size and dipolar moment is calculated using
extension of the recently proposed thermodynamic perturbation theory for
central force (TPT-CF) associating potential. To establish the connection with
the phase behavior of ferrocolloidal dispersions it is assumed that the dipole
moment is proportional to the cube of the hard-sphere diameter. We present and
discuss the full phase diagram, which includes cloud and shadow curves,
binodals and distribution functions of the coexisting daughter phases at
different degrees of the system polydispersity. In all cases studied
polydispersity increases the region of the phase instability and shifts the
critical point to the higher values of the temperature and density. The larger
size particles always fractionate to the liquid phase and the smaller size
particles tend to move to the gas phase. At relatively high values of the
system polydispersity three-phase coexistence is observed.
