By Sunil Bhardwaj


It is a potential developed when a liquid is forced through a porous membrane or capillary. The oppositely charged layers of electrical double layer are separated when liquid passes through membrane. It results in the development of potential between the two sides of membrane.

Thus, streaming potential is exactly reverse of electroosmosis.

In electroosmosis flow of liquid takes place due to applied potentialIn streaming potential, the potential is developed due to the flow of liquid.

It is possible to measure the streaming potential by using reversible electrodes like calomel electrodes. Such electrodes are kept at two ends of the membrane and potential difference arising due to passage of water or liquid is measured.

Streaming potential (S) and zetapotential \((\xi)\) are related by the equation. $$ \xi = \frac { P\pi \eta kS }{ D } $$ Where, \(\eta\) = viscosity of the medium,
k = specific conductance of the liquid,
P = a pressure applied to cause the flow
D = dielectric constant of the medium.