Gibbs–Donnan effect

The Gibbs-Donnan effect, or Gibbs-Donnan equilibrium, refers to the distribution of ions between two compartments separated by a selectively permeable membrane, typically a biological membrane. This phenomenon occurs when there are impermeant charged solutes in one compartment that cannot freely cross the membrane, influencing the distribution of permeable ions across the membrane due to electrochemical gradients and concentration differences.