Fouling mechanism and cleanability of ultrafiltration membranes modified with polydopamine-graft-PEG

Membrane surface modification via grafting poly(ethylene glycol) (PEG) onto the coated polydopamine (PD) layer is an attractive strategy because it can improve the hydrophilicity of the membrane surface. Sodium alginate (SA), bovine serum albumin (BSA), and humic acid (HA) were used as model foulants to investigate the fouling mechanism and cleanability of modified membranes. The modification narrowed or blocked the membrane pores, which led to a reduction in the permeability of ultrafiltration membranes. A Hermia model was used to explore the fouling mechanism of the modified membranes. PD-g-PEG modified membranes exhibit a lower adsorption for the model foulants and a better cleanability than the unmodified membranes.Keywords: polydopamine, organic matters, PEG, fouling mechanism