An Effect of the Nature of Immobilized Components on the Adsorption and Mass Transfer Properties of Ultrafiltration Membranes Based on Sulfonate-containing Сopolyamide

Ultrafiltration membranes based on aromatic copolyamide, comprising 10% of units with sulfonate groups were produced. The possibility of their use as a matrix for the immobilization of ligands used in affinity chromatography: metal cations, amino acids, and dyes, is shown. The components of immobilization were copper(II) ions, histidine, lysine, and 3,6-diamino-10-methylacridine chloride. It was found that immobilization mainly occurs due to the electrostatic interaction of the corresponding functional groups of the component and copolyamide and is not accompanied by a decrease in the specific membrane productivity in water. The investigations of adsorption (under static conditions and ultrafiltration of protein solutions) were performed as well as mass transfer properties of modified membranes. The nature of the effect of the modification was revealed on the mass transfer characteristics of the obtained materials. For an unmodified membrane, the optimal combination of selectivity and specific productivity was realized at pH of the protein solution above its isoelectric point. Depending on the nature of the immobilized component, selectivity of 0.96–0.99 can be achieved at the pH below or equal to the isoelectric point of the protein.