The name is absent

and the excess free energy includes both intra- and intermolecular interactions. An
advantage of this approach is that the theory predicts the change in the free energy
functional on bonding an ideal gas of segments to form an ideal gas of chains, in
terms of the segment densities. The excess free energy is also derived in terms of seg-
ment densities by treating the polyatomic system as a mixture of associating atomic
segments in the limit of complete association (similar to SAFT [46] for homogeneous
fluids). This leads to a DFT that offers accuracy comparable to molecular density
based theories at a computational expense comparable to those of atomic DFTs. The
theory was successfully applied to study polymer melts, solutions and blends con-
fined in slit-like pores. Dominik et. al. [114] extended the theory to real systems
and calculated the interfaciaΓ properties of n-alkanes and polymers. All these appli-
cations were for homonuclear chains (chains having similar segments). Limitations
of the Tripathi and Chapman form of DFT are seen most clearly when applied to
heteronuclear chains. Since a segment in a chain only knows about its nearest neigh-
bors, information about unlike segments is not shared sufficiently along a chain. For
example, in block copolymers, one block has little information about the other block.
One consequence is that the theory does not constrain the overall stoichiometry of
segments in the system. Overall stoichiometry means that the average densities of
all the segments on a molecule in the system are equal. These limitations are present
because the stoichiometry was assumed in the derivation of the theory rather than
having the theory enforce stoichiometry.

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