Microphase Separation Transition for Polyelectrolyte Gels in Poor Solvents

The microphase separation transition in the weakly charged polyelectrolyte gels immersed in poor solvent and undergoing collapse transition is studied in the weak crystallization approximation. The chain connectivity in the gel is taken into account via introducing “polarization" term first proposed by de Gennes. It is shown that in this case the gel can undergo multistage jump–like collapse where the intermediate states can have regular microstructures of different symmetry. The availability of numerous metastable states in the collapse region may lead to the pronounced hysteresis effects. These results are compared with some of the recent experimental findings