A new application of the open-ended conductimetric capillary cell for measuring thermodynamic diffusion coefficients of electrolytes in polymers of different hydrophilic character is presented. Diffusion coefficients of potassium chloride in hydrophilic (PVA) and hydrophobic (POxB) polymers have been measured and prove the applicability of the cell to measure diffusion coefficients in polymer-solvent-electrolyte systems. The theoretical basis of the method is the formulation of diffusion equations in terms of the chemical potential gradient of the diffusing species, and the validity of this approach has been justified by experimental results.
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