The natural bio-macromolecules in aqueous solutions are normally charged macroions surrounded with counterions. Such polyions perform conformational transition such as coil-to-helix, which is closely related with the thermodynamics and dynamics of the counterions. The coil-to-helix and the sol-gel transitions of the polyion dispersions of kappa-carrageenan have been revealed by the frequency dependent dielectric and electrical properties, which is attributed by the bound and free counterions. The dependences of the relaxation time and dielectric increment on the temperature, ionic strength, and polymer concentration have also been investigated.
