Switching of Water Flow Through Stimuli-responsive Hydrogels

Abstract

ABSTRACTThe friction between the polymer network and the solvent water was measured by a newly designed simple apparatus where the hydrogel was mechanically constrained in a glass microcapillary. The water-flow through the hydrogel could be continuously controlled by more than ten times only by adjusting the temperature in the vicinity of the transition temperature (around the human body temperature). The concentration of polymer network and cross-linker as well as the inhomogeneity of polymer networks introduced at gelation was found to determine the overall flow velocity and the amount of change during the phase transition could be controlled by the temperature change. The principle to control the solvent flow will be discussed on the basis of the material parameters and the experimental conditions.