The name is absent

segments the same) both the end- and mid-segment densities of the polymer decrease
near the surface.

As mentioned earlier, the contact density of the confined polymer at the hard wall
is related to the pressure or the compressibility factor of the polymer fluid at the bulk
density in the confinement. To test the accuracy of modified iSAFT, we calculate the
compressibility factor of star polymer fluids from their contact and bulk densities in
the confined space and compare with the simulation data of Yethiraj and Hall [264].
Figures 7.8a and b shows the comparison for 3-arm and 4-arm star polymer fluids.
Modified iSAFT is in excellent quantitative agreement with simulation results.

7.4 Conclusions

The formulation of modified iSAFT is extended to branched polymers. The the-
ory is applicable to polymer chains with complex branched architectures and different
blocks having different chemistry. To test the accuracy of the theory, it has been ap-
plied to study the microstructure of (athermal) star polymers confined between two
planar surfaces, where the width of the confinement is of the order of molecular
diameter. Like athermal linear polymers, the microstructure of confined star poly-
mers is also governed by the competition between the packing and configurational
entropie effects. At lower polymer concentrations, polymer chains are depleted near
the confining surface due to loss in configurational entropy. On the contrary, at higher
concentrations, packing effects enhances the polymer chains near the surface. Com-

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