Dimensional and concentration dependences of diffusion of aqueous alkaline-earth metal nitrate solutions in porous-glass membranes

Diffusion coefficients characterizing penetration of aqueous solutions of magnesium, calcium, strontium, and barium nitrates across porous-glass membranes with predominant pore radii of 4.5–70 nm were determined. A decrease in the pore radii of the membranes is accompanied in all cases by an exponential fall of the diffusion mobility. A reversal of the diffusion mobility series was observed for membranes with pore radii of 4.5 and 70 nm on the background of the general tendency toward a concentration-related rise in the diffusion coefficients.