On the theory of weakly charged polyelectrolytes

The problem of the possible regimes of the qualitatively different behaviour of solutions of weakly charged polyelectrolytes in theta- and good solvents are considered. For both cases we constructed the diagram of states with the following variables: polymer concentration in solution and concentration of added low-molecular weight salt. We also describe the behaviour of a polyelectrolyte solution in each of the regimes. To obtain the diagram of states it was necessary to solve the problem of the Debye-Hückel screening by non-point-like objects. This problem is considered in the Appendix.