Adsorption of polymers from semi-dilute solutions

6 ADSORPTION OF POLYMERS FROM SEMI-DILUTE SOLUTIONS 

C = C (or in volume fractions, 0=0), the coils begin to touch each other at the concentration corresponding to the threshold of overlapping. This threshold is not sharp and a region of crossover exists. Concentration C shordd be comparable with the local concentration inside the coil. 

A generalized approach gives the possibility to consider the transition conditions from semi-dilute to concentrated solutions. For statistical coils, the critical concentration of overlapping (cross-over concentration) is expressed as 

Adsorption of polymers on adsorbing particles of varying sizes is concentration specific. The analysis of such adsorption is very difficult, and to describe the experimental data, the first crossover concentration, where macromolecular coils begin to overlap and interact, can be used. Therefore we can use the simple criterion of transition from dilute to semi-dilute solutions7  

To prove experimentally the adsorption of aggregates, we have used the method of turbidity spectra, which allow us to estimate the aggregate size and their number in solution. The comparison of these data with adsorbance shows that aggregates are transferred onto the adsorbent surface (their number 

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