MICROPHASE SEPARATION OF CHARGED DIBLOCK COPOLYMERS - MELTS AND SOLUTIONS

The microphase-segregation properties of diblock copolymers composed of a neutral polymer joined to a polyelectrolyte are described. For weakly charged diblocks under melt conditions, a theory for weak concentration fluctuations is constructed in order to determine the limit of stability of the mixed phase. We present a scaling analysis of the ordered phase and find that the osmotic pressure of the counterion gas tends to disorder the strongly segregated system. We also consider the behavior of the diblocks in a solvent that is poor for the neutral block but which dissolves the charged block; we carry out a mean-field study of the formation of micelles and their properties.