title: Cyanobacterial polysaccharide gels with efficient rare-earth-metal sorption.
abstract: The cyanobacterial polysaccharide sacran, which contains carboxylate and sulfate groups, was extracted from Aphanothece sacrum , and the metal sorption behavior of sacran was investigated. Heterogels, where the sacran chains were trapped by polyvinyl alcohol networks, were prepared and immersed in NdCl3 solutions to shrink and cloud due to Nd binding. These heterogels had the ability to sorb excessive amounts of Nd ions, more than the stoichiometric ratio of 1:3 (sacran anion/Nd). Furthermore, the sacran-containing gels sorbed Nd ions under highly acidic conditions below pH 2 more efficiently than alginate-containing gels. We speculated that the strong Nd condensation effect of the sulfate groups in sacran under the acidic conditions may enhance the Nd sorption to the carboxylate groups.
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
authors.forename: Maiko K
authors.initials: MK
authors.lastname: Okajima
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nakamura
authors.forename: Tetsu
authors.initials: T
authors.lastname: Mitsumata
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Kaneko
mesh_terms: D000327:Adsorption; D001665:Binding Sites; D000458:Cyanobacteria / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D008674:Metals, Rare Earth / Q000302:isolation & purification*; D011134:Polysaccharides / Q000737:chemistry*
chemical_list: D005782:Gels; D008674:Metals, Rare Earth; D011134:Polysaccharides