Investigation of water absorption by electrically stressed polythene

Experiments are described in which a metal electrode was applied to one side of a polythene disc about 1 mm thick while the other side was in contact with an electrolyte. It is shown that the rate of absorption of water depends both on the ions dissolved in the water and on their concentration. The passage of water through polythene is attributed to the action of the field on hydrated ions which move from the electrolyte into, and through the polythene. This conclusion is supported by chemical analysis of specimens which had been in contact with NaCl solution and in which sodium was found after a period of stress with the appropriate polarity. The rate of water flow depended on the applied voltage and not on the electric stress. It is concluded that water entered only at a few points, distributed over the surface area of the disc, and spread from these to the opposite electrode, but the transport process is more than that of a cloud of hydrated ions sweeping through the polythene.