lfo
Figure 1.2: Schematic of the microstructure of a polymeric fluid adsorbed at a surface:
scaled total segment density (p(z)/pιmik) as a function of the scaled normal distance (z∕σ)
away from the surface.
fundamental interest to many practical processes, such as lubrication, membrane sep-
arations, chromatography, and enhanced oil recovery.
The major challenge in modeling the thermodynamics and phase-behavior of inho-
mogeneous systems is to obtain the microstructure of the fluid. Once the microstruc-
ture is obtained, other thermodynamic properties can be obtained using standard
thermodynamic relations. The challenge of accurately predicting this structure mul-
tiplies manifold for a polymeric fluid, mainly due to both intra- and inter-molecular
correlations between the segments of the polymer molecules. For example, a modest
surface-fluid interaction per segment translates to a large surface-fluid interaction per
molecule. Again, conformational entropy due to the intramolecular correlations of
the polymer chains plays a predominant role in determining the microstructure of
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