The structure‐breaking effect on oxygen diffusion coefficients in electrolyte and polyelectrolyte solutions

Abstract

AbstractBy employing a membrane‐covered polarographic oxygen electrode, the oxygen diffusion coefficients and solubilities in aqueous solutions of ammonium chloride, potassium iodide, sodium alginate, sodium carboxymethylcellulose (CMC), and xanthan gum have been measured with a newly developed methodology. Experimental results showed that in all systems studied, oxygen solubilities decrease on addition of solutes. Oxygen diffusion coefficients in aqueous solutions of KI and NH4C1 are found to be higher than that in pure water. In sodium alginate solutions, dilute xanthan solutions, and solutions containing more than 0.3 wt% of CMC, oxygen diffusion coefficients decrease with an increase in polymer concentrations. Interestingly, in dilute CMC solutions and concentrated xanthan solutions containing more than 0.5 wt% of xanthan gum, oxygen diffusion coefficients increase with increasing polymer concentrations, and values exceeding that in pure water are generally observed.