Alginate polyelectrolyte ionotropic gels

The kinetics and mechanism of exchange of Ni²⁺ by H⁺ ions in ionotropic nickel alginate polymembrane gels of capillary structure have been studied by pH-metric and conductimetric techniques. The rate of exchange conforms to; rate=k₁ [nickel alginate] [H⁺]- k_–1 [alginic acid] [Ni²⁺] with k₁=6.34×10^–2dm³mol^–1s^–1 and k_–1=8.83×10^–4 s^–1 at 20°C, respectively. The activation parameters have been evaluated and a mechanism consistent with the kinetic data is discussed.