Prevailing cation interchange

Prevailing cation interchange shrinking the material during the oxidation processes and swelling during reduction (accepted for families 3 and 6) ... 

The important role played by the water interchange in both oxidized and reduced materials is an unsolved point, in particular when prevailing cation interchanges are present. In most of the systems, during oxidation there coexist the entrance of anions and the expulsion of cations. 

Due to the complex nature of the polymer-ion interactions (i.e., polymer films act as membranes attaining a thermodynamic equilibrium between anions and cations in the polymer and in solution), any real system involves interchange of either anions or cations during an electrochemical process. Usually one of those interchanges prevails for the different families of CPs. Two main basic ideal electrochemical mechanisms are accepted as the origin of the volume variations ... 

---