The name is absent

is obtained, and the predictions are in better agreement with experimental data for
asymmetric mixtures of n-alkanes than PC-SAFT. The next section of this chapter
provides a detailed description of SAFT-D. The results obtained for the homologous
series of n-alkanes, long chain alkanes, and polymers are discussed in the subsequent
section. SAFT-D predictions are compared with results obtained from the PC-SAFT
model for both monodisperse and polydisperse polymer solutions.

2.2 SAFT-D equation of state

Consider a mixture of chain fluids such that the chain fluid of type T has ⁱm_i^,
number of segments, σ_l is the size of their segments (i.e. homonuclear polymer chains),
and x_i is their (number) fraction in the mixture. For total ‘N’ number of chains in
the mixture, the Helmholtz free energy is given in terms of a perturbation expansion
as

A = A^id + A^fes

where, A^ld is the ideal free energy of segments, and the various excess contributions
to the free energy are: A^hs due to volume exclusion∕repulsive interactions, A^cham
due to chain formation, and A^dτsp due to the dispersive∕attractive interactions. It is
clear from eqn. 2.1 that there are two perturbations involved. First one (chain term)
derives the free energy of hard-chain fluid using perturbation from a reference fluid
of hard spheres in case of SAFT-HS and hard dimers in case of SAFT-D, while the
second one (dispersion term) derives the free energy of the attractive chain fluid using

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