namic perturbation theory (TPTl). For the homogeneous polymer systems, a number
of engineering equations of state based on TPTl have been developed. These EOS
depict the polymer molecule as a fully flexible chain of tangentially bonded spheres.
Such a model, albeit simple, capture the essential features of polymer systems, namely
excluded volume, and chain connectivity. One of the shortcomings of these EOS is
that neither of them are able to provide an accurate description of the phase behavior
of polymer solutions over the whole range of polymer weight fractions. Chapter 2
proposes a new improved EOS based on TPTl, and validates it by comparisons to
experimental data for n-alkanes, and polymer solutions.
The success of TPTl for bulk homogeneous polymer systems has triggered the
interest of researchers to formulate TPTl in a density functional theory (DFT) for-
malism for inhomogeneous polymer systems. Chapter 3 presents a brief background
on DFTs based on TPTl. Rather than rigorously forming polymer chains starting
from associating atomic fluids in the inhomogeneous conditions, these DFTs use the
final expression for the homogeneous free energy of polymer chains (from SAFT),
which only accounts for indirect intramolecular interactions due to volume exclusion.
Thus, the intramolecular interactions due to direct bonding between the segments are
included into the ideal chain term. This ideal chain term is based on multi-point-based
molecular density, Pm(R) (R = {rι,r2,..., rm} where ri is the position of segment T
in the polymer chain with ‘m’ segments), which makes the computations expensive.
In the current research work, the rigorous approach of starting from inhomogeneous
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