Nematic-fluid structure in wall-field geometry. II. The direct correlation function.
An explicit expression for the wall-nematic direct correlation function (DCF) is obtained for any orientation of the wall with respect to an external orienting field. It is found that inside the surface of the wall, the DCF rapidly tends to a function of the nematogen orientation and depends only on parameters of the bulk fluid. We suggest that the wall-nematic DCF can be used as an ansatz for the colloid-nematic DCF in dilute nematic colloids. The reliability of this ansatz is investigated at different field strengths in both isotropic and nematic regions. Our calculations for spherical colloidal particles show that this approximation is valid for colloidal particles that are large, but well within the physically realistic size range. The ansatz could also be applied to nonspherical colloidal particles.
Sokolovska
T G
TG
Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Sokolovskii
R O
RO
Patey
G N
GN