segments bonded tangentially to each other. Since, these are fully flexible chains, the
angular dependence of the sites on the segments is relaxed and the site-site structural
properties of the segments such as Mayer-f function are averaged over all possible
orientations. Hence, eqs. 1.4 and 1.5 reduces to
Aassoc ι∙ m ___ / γi (r,∖ -∣ ∖
-—= £ In⅛) - + i) , (1.6)
∕v-Z / ∖ Zi Zt ι
j i=ι Aerω v z
and
where
∆4*sfy,r') = fAB(r,r')greS{v,T')KA^. (1.8)
Ka,b> is a constant geometric factor resulting from averaging the orientation con-
straints that the segments must satisfy to form a bond. Another assumption is that
bonding at a site of a segment is independent of bonding at its other sites. The
derivation of SAFT as an EOS for homogeneous polymeric systems is the focus of
next chapter while the development of modified iSAFT as a new DFT for a range
of inhomogeneous polymeric systems is the crux of the rest of this dissertation. It
has to be pointed out that a remarkable characteristic of these theories based on per-
turbation is their flexibility for adding contributions to the free energy to explicitly
account for all the interactions present in the fluid mixtures, such as dispersion, polar
or induced dipole interactions. For example, the free energy of a chain-fluid with
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