where,
4⅞V) = 4¾
(6.25)
rc is the potential cut-off, σij — (σi + σj∙)∕2 and eʊ = yJtitj- If rc = 21∕6σ⅛ then
the potential is purely repulsive. To include attraction the range of LJ interaction
(or potential cut-off) is extended to rc = 2.5σij. In modified iSAFT, the long range
attractions are added as a perturbation to the hard repulsion (reference fluid). For
the LJ potential, the attractions are treated in the spirit OfWeeks-Chandler-Anderson
(WCA) perturbation theory [120, 121].
uij(r) = uτ^{r) + uɑf(r),
(6.26)
where
if r < ay-
otherwise
(6.27)
and
<i(r) = <
Ui-j(rmin) - r⅛7(rc) σij <r <r.
(6.28)
Uijj(r) - u⅛,(rc)
Tmin — T
rmm = 21∕% is the position of the (LJ) potential minima.
We first studied the structure of hard (athermal) chains tethered to a flat hard
surface. This corresponds to the case where chains are present in an implicit good
solvent. The chains are assumed to be uniformly distributed on the surface. Hence
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