3.4 Segura, Chapman and Shukla
Segura et. al. [62] developed a density functional theory for associating hard
spheres to study their structures against a hard wall (hydrophobic surface). The
theory was based on Wertheim’s TPTl. The theory was derived for associating fluids
with four bonding sites but is general for any number of sites. They developed two
ε∕W> '∣2 *∙ C¾∣ *■ ⅛,¾2 < ⅛
0, otherwise
Figure 3.1: Schematic of the associating hard spheres with four associating sites placed
in tetrahedral symmetry on the spherical core: sites A, B, C are outside while site D is
inside the plane of the paper, Φab is the association potential between two sites A and B
on different associating spheres.
The first version was again based on the fact that Wertheim’s theory was derived
in general for inhomogeneous systems as noted by Chapman [58] and Kierlik and Ros-
inberg [59, 100]. The model considers spherical atoms with a hard core and highly
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