Preparation and performance of cellulose acetate-polyurethane blend membranes and their applications. Part 1

Ultrafiltration gains significance when certain chemical species, such as proteins and some toxic heavy metal ions, present in low concentration, have to be selectively removed from a mixture. Separation of metal ions by complexation with macromolecular binding agents and rejection of proteins such as bovine serum albumin, egg albumin, pepsin and trypsin was studied using cellulose acetate–polyurethane blend ultrafiltration membranes. The influence of the composition of the polymers in blend membranes on the separation of metal ions and proteins is discussed. The blend membranes were also characterized by pure water flux, water content, membrane hydraulic resistance, molecular weight cut-off and scanning electron microscopy. The separation of proteins was found to be directly proportional to the molecular weight of the proteins, while the flux displayed an opposite trend, and copper was found to have a higher separation capability than nickel, zinc and cadmium.