3. Material transport across a membrane

Under the action of an active force, the passage or stopping of substances takes place according to the possibility of passage by convection, migration or diffusion.

The selectivity of the artificial membrane therefore depends on its ability to distinguish substances by steric effect, ionic exclusion or preferential solubilization.

It should be noted, however, that it is essential for the force applied to have an effect on the substance in question.

In addition, the substance must be in a fluid medium to be able to move. The table at 1 shows the relevant states of matter in blue.

Finally, depending on the type of membrane used, the physical state of the substances to be separated and the form of energy used, the fine separation achieved...