(195b) Preparation of High-Capacity, Weak Anion-Exchange Membranes for Protein Separations Using Surface-Initiated Atom Transfer Radical Polymerization

When used as chromatography media, synthetic microporous or macroporous membranes offer advantages over resin-based media, such as low pressure drop, high production rate, and facile scale up and set up. In this presentation, we will describe how to surface modify commercially available regenerated cellulose membrane by atom transfer radical polymerization to produce high-capacity (>50 mg/mL) anion-exchange membranes for protein chromatographic separations. The monomer 2-dimethylaminoethyl methacrylate was polymerized from the pore surface of cellulose membranes to convert them into weak anion-exchange membranes. Physicochemical properties of surface-modified membranes were studied as a function of polymerization time with various analytical measurement techniques that include scanning electron microscopy, atomic force microscopy, and attenuated total reflectance FTIR. Performance properties that were measured include buffer permeability and static protein adsorption capacities. Kinetic studies of surface-initiated ATRP using model flat substrates were performed to approximate three dimensional polymer nanolayer thickness evolution during graft polymerization from membrane surfaces.