Counterion-induced solubilization

Both chemically and electrochemically synthesized PPy s are typically insoluble in water and organic solvents, and are infusible because of strong intermolecular and intramolecular interactions of their polymer chains. There has been intense research over the past decade to overcome this serious hindrance to their proces-sibility and subsequent utilization. Several approaches have now been developed to improve the solubility of PPy s, namely (1) counterion-induced solubilization, (2) colloid formation, and (3) side-chain-induced solubilization. Each of these will be discussed in turn. 

From experiments of this type it is possible to draw conclusions about the location of the solubilized molecules in the micelles since the counterion relaxation is sensitive to the charge density at the micellar surface. It could, in the case considered, be deduced that hexanol, benzene and N,N-dimethylaniline, which cause a marked lowering of the relaxation rate at high concentrations, are mainly solubilized at or near the interface between the micelle and the intermicel-lar solution. Cyclohexane, which does not affect counterion relaxation, appears to be located in the micellar interior. Furthermore, it was deduced that the first three compounds promote the sphere-to-rod transition, whereas no shape alteration is induced upon solubilization of cyclohexane [Z21],... 

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