A. A. Zagorodni Ion Exchange Materials: Properties and Applications Elsevier:2006
Book - Applets - Applet 7

Applet 7

Gregor's model of ion exchange resins

The matrix of the resin is assumed to be a network of elastic springs. When the resin swells, the network is stretched and exerts a pressure on the internal "pore" liquid, as the skin of an inflated toy balloon exerts a pressure on the air inside.

The "swelling pressure" can be altered moving the slider.