Abstract:
It has been demonstrated that when a low-molecular-weight salt solution flows
through a polyelectrolyte gel, an electromotive force is generated, and its polarity depends
on the sign of the polyelectrolyte network’s charge. A mathematical model proving the possibility of developing a device for separating a solution of low-molecular salt into enriched
and depleted phases under the influence of gravitational forces has been developed. Such
a device contains a system of parallel columns filled with different kinds of cross-linked
polyelectrolyte networks. The proposed mathematical model is grounded in the theory of
double electrical layers forming at the hydrogel/solution interface; these layers deform
under non-equilibrium conditions, specifically during the flow of the solution through the
cross-linked polyelectrolyte network. An analogous model is proposed describing the case
of an analogous device based on an electric current passing through two oppositely charged
contacting networks, which provides the possibility of separating the initial solution into
enriched and the depleted phases too. The practical applications of the found effect are
discussed. In particular, it is demonstrated that a wide number of measurement electronic
devices can be created on such a base, including devices to be used within the investigation
of polyelectrolyte hydrogels of different types.
