Weak adsorption of a single chain

This situation is again described by Fig. 1.6. To determine the thickness of the adsorption layer D, we write, instead of eq. (1.13), an energy per chain of the form 

These equations should apply for 1 8 N (the latter inequality corresponding to ) Rp). 

Monte Carlo studies on chains near an adsorbing surface have been carried out, but the small 8 limit is not very well known. 

On the physical side, there are many complications. As mentioned, single-chain adsorption is never observed. One always reaches a situation where many chains compete for the same portion of surface. Furthermore the single-chain problem may be modified by the existence of long range van der Waals forces between the surface and each monomer. The corresponding potential decreases relatively slowly (as D ) and the attraction energy may not be cast into the form used in eq. (I.S7). 

Selected Papers on Noise and Stochastic Processes, N. Wax, Ed., Dover, New York, 1954. 

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