Use of graft-modified membranes for water treatment

Membranes with designed surface and filtration properties were prepared by grafting and adsorption of polyelectrolyte multilayer systems on membrane surfaces using the layer-by-layer electrostatic self-assembly technique. Microfiltration membranes with a first polyelectrolyte layer grafted onto the surface showed excellent stability during the filtration process. Although a two-fold higher permeate flux was observed for a three-layer polyelectrolyte complex membrane compared to a just grafted one, the protein retention did not change remarkably. Additionally, a reduced protein adsorption was detected by in-situ ATR-FTIR spectroscopy for the case of repulsive electrostatic forces between the substrate and the protein under applied test conditions.