Reactive & Functional Polymers, Vol.73, No.3, 550-554, 2013
Emulsion gel beads prepared by sedimentation polymerization using two-fluid atomization and their Pd(II) ion adsorption properties
An emulsion gel adsorbent which was a polymeric hydrogel containing randomly distributed oil micro-droplets of an extractant was developed for improved metal adsorption in our previous study. This study focuses on the preparation of monodisperse, millimeter- or sub-millimeter-sized emulsion gel beads, for which a novel production method combining sedimentation polymerization and two-fluid atomization is proposed. The method involves the drop-wise addition of a pre-gel oil-in-water emulsion solution into a silicone oil through a nozzle, with nitrogen gas flow, and the subsequent free-radical polymerization of the pre-gel droplets during their descent. A novel type of emulsion gel bead composed of a poly(ethylene glycol) methyl ether acrylate hydrogel and di-n-hexylsulfide as an extractant was developed. The size of the emulsion gel beads was controlled by adjusting the gas flow rate. The emulsion gel beads successfully adsorbed Pd(II) ions that were used as a model metal. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords:Spherical gel beads;Emulsion;Sedimentation polymerization;Two-fluid atomization;Metal adsorption