In films of the polyelectrolyte complexes of glycol chitosan (gc) with alginic acid (aa) and hyaluronic acid (ha) anomalously large dielectric dispersion was observed in the range 1 to 100 kHz above 50‡C. This was attributed to the formation of electrical double layers around the polyanion by the sodium ions inevitably present in the films.
To test this hypothesis films ofgc with carboxy methyl cellulose were prepared with different concentrations of lithium, sodium and potassium ions. The films were found to absorb much larger amounts of sodium than lithium or potassium. Dielectric measurements from −40 to 80‡C in the range 1 to 100 kHz showed anomalously large dispersion above 50‡C in films with the higher concentration of alkali ions. The dispersion could be fitted to Schwarz’s equations. The characteristics of the fit were similar to those in GC-AA and GC-HA films supporting the hypothesis that the anomalous dispersion is due to an electrical double layer formed around the polyanion by the alkali ions.