| Abstract: | The dc electrical conductivity of films of the polyelectrolyte complexes of glycol chitosan (GlChi) with the sodium salts of dextran sulfate (DS), carboxymethyl cellulose (CMC), polygalacturonic acid (GalUA)n, and alginic acid (AlgA) was measured at temperatures above and below room temperature. The maximum field strength in the thinnest film used amounted to 3 × 104 V/cm. A plot of normalized current against the reciprocal of the absolute temperature revealed two regions with different slopes, and activation energies in these two regions have been obtained for all the complexes. The activation energies in the high-temperature region vary from 0.85 to 1.18 eV and in the low-temperature region from 0 to 0.22 eV. Reasons are given to show that the conductivity is probably ionic. Near room temperature, the current–voltage relation is almost linear in the GlChi–DS complex, while in the other three complexes the current varies as a power n of the voltage with the value of n ranging from 1.7 to 2.5. A rise in temperatures causes an increase in the slope of the log I vs log V plot in GlChi–DS and GlChi–CMC complexes. The nonlinear current–voltage relation is ascribed to a space-charge-limited conductivity. |
