Alginate gel beads filled with halloysite nanotubes

Novel hybrid gel beads with a well defined and controlled size formed by alginate biopolymer and halloysite (Hal) nanotubes were designed, prepared and characterized from the physico-chemical viewpoint. The thermogravimetry made it possible to determine the water content, the total as well as the local compositions of Hal into the gel beads. Dielectric spectroscopy evidenced that Hal reduced the fluctuation of ions. The SEM micrographs showed that the dried beads exhibit a rough surface, with pores in the micrometer range. In addition, the concentration of nanotubes was higher into the bead core at a higher overall loading. The performance of these materials was verified with the specific purpose of adsorbing crystal violet from aqueous phase. The alginate gel beads populated by Hal improved their ability to capture the dye so that they can have important implications in the enhancement of controlled adsorptions. (C) 2012 Elsevier B.V. All rights reserved.