Restriction of biofouling in membrane filtration using a brush-like polymer containing oligoethylene glycol side chains

We investigated the effect of an amphiphilic comb polymer on reducing nonspecific adsorption of biomolecules in membrane filtration. The amphiphilic comb polymer is a methyl methacrylate-based coating material with short nonfouling oligoethylene glycol side chains that provides long-term, bio-repellant surfaces. The nonfouling property of this polymer on a commercially available filtration membrane was observed through cyclic filtration–washing processes of microbial, alginic acid, and bovine serum albumin solutions. The chemical structure and properties of the synthesized comb polymer were determined by Fourier transform-infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and gel permeation chromatography (GPC), while the permeation characteristics of the hydrophobic polysulfone membrane and comb polymer coated membranes were examined using home-built ultrafiltration cross-flow sets. Membranes coated with the comb polymer showed higher flux recovery than control membranes after a five-cycle filtration–washing process. Taken together, this shows that the comb polymer effectively inhibits the fouling of membrane surfaces by biomolecular materials.