| 释义 |
Gibbs-Donnan equilibrium
Gibbs-Donnan equilibrium[¦gibz ′dän·ən ē·kwə′lib·rē·əm] (physical chemistry) Donnan equilibrium Gibbs-Donnan equilibrium
Don·nan e·qui·lib·ri·um (don'ăn), when a semipermeable membrane or its equivalent (for example, a solid ion exchanger) separates a nondiffusible substance, such as protein, from diffusible substances, the diffusible anions and cations are distributed on the two sides of the membrane so that 1) the products of their concentrations are equal, and 2) the sum of the diffusible and nondiffusible anions on either side of the membrane is equal to the sum of the concentrations of diffusible and nondiffusible cations; the unequal distribution of diffusible ions thus produced creates a potential difference across the membrane (membrane potential). Synonym(s): Gibbs-Donnan equilibrium [Frederick G. Donnan] Donnan, Frederick G., English physical chemist, 1870-1956. Donnan equilibrium - the equilibrium of small ions between a solution with charged macromolecules, and one without. Synonym(s): Gibbs-Donnan equilibriumGibbs-Donnan equilibrium - Synonym(s): Donnan equilibrium
Gibbs, J. Willard, U.S. mathematician and physicist, 1839-1903. Gibbs energy of activation - energy that must be added to that already possessed by a molecule(s) in order to initiate a reaction.Gibbs free energyGibbs theorem - substances that lower the surface tension of the pure dispersion medium tend to collect in its surface, whereas substances that raise the surface tension tend to remain out of the surface film.Gibbs-Donnan equilibrium - Synonym(s): Donnan equilibriumGibbs-Helmholtz equation - an equation expressing the relationship in a galvanic cell between the chemical energy transformed and the maximal electromotive force obtainable. Synonym(s): Helmholtz-Gibbs theoryHelmholtz-Gibbs theory - Synonym(s): Gibbs-Helmholtz equation |