Rheological Effects of Polymer Membrane Swelling in Water and Their Dependence on Isotopic Composition

It is shown that swelling of an initially hydrophobic Nafion plate in a cell of limited volume follows a different way in ordinary water (deuterium concentration 157 ppm) and in deuterium-depleted water (deuterium concentration 1 ppm). Small variations in the deuterium concentration in water turn out to lead to a considerable difference in swelling dynamics of the polymer membrane. For a Nafion plate 175 µm thick, this effect is most distinct at the distance between the windows L = 200 µm.