Surface interactions in osmotic pressure controlled flux decline during ultrafiltration

Abstract

Prediction of osmotic pressure controlled flux decline during ultrafiltration requires an accurate theoretical determination of the osmotic pressure of macromolecular solutions at high concentrations, where non-van't Hoffian contribution becomes significant. A model for osmotic pressure determination is used which is based on facile measurements of surface properties of solutes. The knowledge of the apolar and polar (acid-base) interaction energies of polymeric molecules in water leads to the determination of the Flory-Huggins interaction parameter. Estimates of the interaction parameter as a function of the solute concentration lead to the direct theoretical prediction of osmotic pressure of various macromolecular solutions up to high concentrations approaching the gel limit