critical values of a still follow the scaling relation, pg∖∕~N g oc 0Γ2 with different pro-
portionality constant. We have shown that this proportionality constant depends on
/?3, and that the critical values of a or the boundary between the purely repulsive
and attractive domains for different β scale as, ps√QVs∕33 oc a~2.
Appendix: Derivation of the force of interaction between
the two polymer grafted hard walls
The grand free energy is given as
Ω[p(r}] = A[p(r)] - 52 / Pα(rK(r)dr, (6.30)
a *'
where ua(r) = μa- V^art(r), and a = {1,..., Ng, 1,..., Ng, 1,..., Nf}. Here the first set
in a or {1,..., Ng } corresponds to the segments in the chains grafted to the surface
at z = 0, the second set {1,..., Ng} corresponds to the segments in the chains grafted
to the surface at z = H, and the third set {1,..., Nf} corresponds to the segments in
the free polymer chains. In this work, Ng — Ng = Ng.
In a density functional formalism,
and
= ~pa^' (6’32)
Force of interaction between the surfaces is given by the functional derivative of
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