Characteristics of a useful ion exchanger:

A useful ion exchanger must have the following requisites:

i) It should have negligible solubility in the medium to be used.

ii) It must contain sufficient number of accessible ion exchanger groups and it must be chemically stable.

iii) It must be sufficiently hydrophilic to permit diffusion of ions through the structure at a finite and usuable rate.

iv) The swollen exchanger must be denser than water.