Journal of Membrane Science
H.K. Lonsdale · 1976
Transference is independent of solvent unless solvent-membrane interaction occurs, making it a more comprehensive parameter than permeability.
Plain English Summary
The parameter called transference is defined as the mass of solute transferred from a saturated solution under perfect sink conditions across the membrane per unit time and area multiplied by the membrane thickness. Permeability coefficients differ for each donor solvent while transference is independent of solvent unless solvent-membrane interaction occurs.
Why This Matters
Transference equals the product of membrane thickness and solute flux from a saturated solution, or permeability times donor solvent solubility, or diffusion coefficient times membrane solubility. In a two-chamber experiment, progesterone diffused from a water solution at 0.75 saturation to a polyethylene glycol solution at 0.1 saturation until both reached equi-activity at 0.1 saturation.
Finding
When transference is introduced into Fick's law it is immediately obvious that the flux of solute through the membrane, at equal fraction of saturation in any donor solvent, is equal and independent of the donor solvent in the absence of solvent—membrane interaction, when the solute has a constant solvent—membrane partition coefficient.
In their words
“When transference is introduced into Fick's law it is immediately obvious that the flux of solute through the membrane, at equal fraction of saturation in any donor solvent, is equal and independent of the donor solvent in the absence of solvent—membrane interaction, when the solute has a constant solvent—membrane partition coefficient.”
Show BibTeX
@article{journal_of_membrane_science_g6301,
author = {H.K. Lonsdale},
title = {Journal of Membrane Science},
year = {1976},
}