Interpolymer association, aggregation

Important evidence for intrapolymer self-organization to form unimer micelles is that the Stokes radius is independent of the concentration. If interpolymer association occurs, the size of the aggregate should increase sig-... 

Fluorescent hydrophobes (naphthyl and pyrenyl groups) incorporated into the polysulfobetaines are a powerful tool for studying the formation of intra-and interpolymer aggregates in aqueous and aqueous salt solutions [85,229-231]. Intermacromolecular hydrophobic association is observed as an increase in the excimer emission relative to that of the monomer emission, where h/Iu is the ratio of intensities of excimer and monomer fluorescence which reflects the extent of inter/intra macromolecular interactions. Intramolecular micellization is easily monitored by the quenching efficiency of the thallium ions. The decrease of h/Iu reflects the breaking of the intra- and interchain associations in aqueous salt solutions, leading to chain expansion. 

In this variety of associating polymer systems, a few central questions emerge as universal themes. One concerns the structure of multipolymer aggregates. In any system with strong interpolymer forces, one could anticipate interpolymer collapse, gelation, and phase separation as three reasonable consequences of these forces. Why then do many systems exhibit stable equilibrium aggregate... 

In general, unimer micelles are preferentially formed in highly dilute aqueous solutions. As the concentration is increased, however, the hydro-phobic association may not necessarily be an intrapolymer event. If interpolymer open associations occur between the hydrophobes or between the primary micelle units, multipolymer aggregates would be formed instead of the unimer micelles. Whether the intrapolymer closed association predominates over the interpolymer open association depends on primarily the chemical structure or the first-order structure of amphiphilic random copolymers. 

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