 Gibbs–Donnan effect

The Gibbs–Donnan effect (also known as the Donnan's effect, Donnan law, Donnan equilibrium, or Gibbs–Donnan equilibrium) is a name for the behaviour of charged particles near a semi-permeable membrane that sometimes fail to distribute evenly across the two sides of the membrane.The usual cause is the presence of a different charged substance that is unable to pass through the membrane and thus creates an uneven electrical charge.