Temperature-dependence of the electrical conductivity for cross-linked mono- and divalent metal-alginate complexes

The electrical conductivities of Ag (I), Ca (II), Sr (II), Cu (II), Zn (II), Cd (II) and Ph (II)-alginate complexes in the form of circular discs have been investigated as a function of a wide range of temperatures. At lower temperatures, the Arrhenius plot of In delta vs 1/T showed that the electrical conductivity for the silver-alginate complex was gradually increased until it reached a maximum and then began to decrease with temperature, whereas no change in the electrical conductivity was observed with respect to the divalent metal-alginate complexes. Again, at higher temperatures, delta values increased continuously with temperature for both mono- and divalent metal-alginate complexes. X-ray diffraction patterns showed that all these alginate complexes are amorphous in nature. IR absorption spectra indicated the presence of chelated metal ions in the chains of alginate macromolecules. The activation energies have been calculated and tentative conduction mechanisms in good agreement with the experimental results are suggested.