Diffusion of cesium ions labeled with 134Cs in agar gel containing alkali metal chlorides: Obstruction effect and activation energy

The effect of some alkali metal chlorides on obstruction effect and activation energy for the tracer diffusion of cesium ions in agar gel medium is studied using zone-diffusion technique. It is observed that both parameters, extent of obstruction (α) and activation energy (E), decrease with an increasing charge density of the cation of the supporting electrolyte. These trends are explained on the basis of a competitive hydration between ions and agar molecules and the relative distortion in the water structure which is brought about by these different ions and agar molecules, respectively.