Water flow through a stimuli-responsive hydrogel under mechanical constraint

Friction between the polymer network and the solvent water was measured under the conditions that the thermoresponsive hydrogel was mechanically constrained in a glass microcapillary. The water-flow through the hydrogel could be continuously controlled by more than 1x10(2) times only by adjusting the temperature in the vicinity of the transition temperature. The principles to control the solvent flow and the switching velocity by the temperature jump were discussed on the basis of the material parameters and the experimental conditions.