Improvement of separation and transport performance of ultrafiltration membranes by magnetically active nanolayer

The fabrication of novel polyethersulfone membranes with a magnetically active surface nanolayer aiming at the reduction of concentration polarization effect and fouling phenomena is reported. Magnetic nanoparticles (MNPs) with the size smaller than 20 nm were immobilized in boundary layer of the membrane using the polyethylenimine flexible spacer. The surface properties of prepared membrane were characterized by a number of techniques: the thermogravimetric analysis (TGA), X-ray diffraction analysis (XRD), infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM) and Zeta potential measurements. The applicability of magnetically active membranes in ultrafiltration of different polymer solutions was revealed. The immobilization of MNPs on membrane surface allowed to increase the permeate volume flux and mass transfer coefficient due to the reduction of the concentration polarization effect.