Journal of Applied Polymer Science, Vol.119, No.6, 3453-3461, 2011
Preparation of Cellulose-Tungsten Carbide Composite Beads with Ionic Liquid for Expanded Bed Application
Expanded bed adsorption (EBA) is an integrated technology for capturing target biomolecules directly from unclarified feedstock. The adsorbents should be designed specially to ensure the perfect performance of the expanded bed. In this study, an ionic liquid (IL), 1-butyl-3-methylimidazolium chloride, was used to dissolve cellulose directly to prepare cellulose-tungsten carbide composite beads with water-in-oil suspension and cooling/ethanol regeneration. The preparation conditions were optimized, especially for four key factors, the cellulose concentration, ratio of the oil phase to the cellulose solution, stirring speed, and addition of tungsten carbide powder. The results showed that the tungsten carbide powder emerged well in the cellulose matrix as an inert densifier. The composite beads had a spherical appearance, a suitable size and size distribution, an appropriate wet density of 1.32-1.68 g/mL, a porosity of 90-96%, a pore radius of 4565 nm, and a specific surface area of 30-42 m(2)/mL. These results show the potential application for this EBA process. Compared to the traditional technology with cellulose xanthate viscose, the new method with the IL as the nonderivatizing dissolution solvent is technically feasible, has concise processing, and is environmentally friendly. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 3453-3461, 2011