Improved Anti-Fouling Performance of Sintered Alumina Membrane Filters Modified with Grafted-on PEG-Brush Polymer

Fouling of membrane filters is the key performance limiting factor in mem-brane filtration. Thus fouling and anti-fouling have received much attentionin recent years, covering topics from fouling mechanisms and characteristicsto anti-fouling surface modifications. This paper presents a method to achievecontrolled grafting of an anti-fouling poly(ethylene glycol) (PEG) brush poly-mer layer onto a sintered alumina membrane filter surface without reductionof the filter permeability. The obtained PEG layers were characterized usinga broad range of surface techniques including Fourier transformed infraredspectroscopy, ellipsometry, atomic force microscopy, and contact angle mea-surements. Dead-end filtration experiments with PEG-brush modified filtersshowed improved fouling reversibility for the filtration of a BSA solutionand significantly slowed down the fouling rate during filtration of a lysozymesolution. The cross-flow filtration of model lake-water demonstrated improvedfoulant removal for the PEG modified filters during backflush cleaning and thereby increased the overall throughput during a filtration cycle as comparedto the bare membrane filters