A study of the self-diffusion coefficients of chloride ion in membranes and particles of hydrous zirconia as a function of variable chloride ion capacity

Abstract

In acidic media the particles and membranes of hydrous zirconia are shown to behave as variable capacity ion exchangers. Self-diffusion coefficients for chloride ion were measured as a function of the variable capacity for that ion in solutions of varying acidity. The results are shown to be in qualitative agreement with absolute rate theory. It is shown that the measured self-diffusion coefficients are dependent only upon the total chloride ion capacity and unaffected by the relative proportions of free hydrogens and sodium ions in the membrane pores. A new method for preparing stable membranes is described and electrical rectification effects, observed when the membrane separates acidic and basic solutions, explained in terms of the amphoteric nature of the zirconia matrix.