Effect of support on rejection

Generally, a membrane is a composite and is made by forming a skin layer on a support. Then, the support will also affect the rejection, since the support affects the ion flux. In practical terms, however, the effect of support on membrane performances is almost always neglected. In this paper, the effect of support on the rejection is theoretically discussed to find a better structure of support for higher rejection. As the results, it is found that the thicker support is better for higher rejection in the system where the ion flux due to the ion migration is higher than the ion flux due to the solvent drag. On the other hand, if the ion flux due to the ion migration is lower than the ion flux due to the solvent drag, the thinner support is better for higher rejection.