Extension of iSAFT model to grafted polymer chains

2 Extension of iSAFT model to grafted polymer chains 

For other segments, the external potential is just due to a planar hard wall. Furthermore, 

Following these arguments, the density profile of segment a a 1) in the grafted polymer chains is 

Clearly, this derivation is only for the polymer chains grafted to the wall at z = 0. For the case of two grafted surfaces, similar results can be obtained for the polymer chains grafted to the wall at z = H, where H is the separation between the two surfaces. 

The force of interaction between the two grafted surfaces (in the absence/presence of free polymer) at separation H is given by 

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