Alginate metal

Figure 1. NMR spectra of calcium-alginate. Metal loadings of a)4%b) 12% and c) 24%.

Sodium alginate [9005-38-3]. Freed from heavy metal impurities by treatment with ion-exchange resins (Na -form), or with a dilute solution of the sodium salt of EDTA. Also dissolved in 0. IM NaCl, centrifuged and fractionally ppted by gradual addition of EtOH or 4M NaCl. The resulting gels were centrifuged off, washed with aq EtOH or acetone, and dried under vacuum. [Buchner, Cooper and Wassermann J Chem Soc 3974 7967.]... 

Davis, T.A., Llanes, F., Volesky, B. and Mucci, A. (2003) Metal selectivity of Sargassum spp. And their alginates in relation to their a-L-guluronic acid content and conformation. Environmental Science S. Technology, 37, 261-267. 

Lebeau et al. (2002) investigated the sorption of cadmium by viable microbial cells that were free or immobilized in alginate beads by incubating the bacteria in a liquid soil extract medium at pH 5 7 and Cd concentrations of 1 to 10 mg L-1. The percentage of Cd biosorbed reached a maximum (69%) at low Cd concentrations and neutral pH. Thus, the effectiveness of bacteria, inoculated into metal-contaminated soils, would largely depend on the concentration of the metal and its distribution between the biomass and the medium. 

Kuhn, S. P. and Pfister, R. M. (1989). Adsorption of mixed metals and cadmium by calcium alginate immobilised Zoogloea ramigera, Appl. Microbiol., 31, 613-618. 

Figure 3.5 — Reactor system fermenter, 1000 mL metal reactor, 135 ml reactor material, stainless steel (VIIA) AB alginate beads. (Reproduced from [40] with permission of Elsevier Science Publishers).

Figure 7.2 Schematic representation of alginate cross-linking with divalent cations and the chemical structure of the constituent repeat units, guluronate (G) and mannuronate (M). Carboxylate groups present along the backbone (largely from the G residues) interact with multivalent cations to yield metal ion cross-linked gels.

Polyelectrolyte-based dental cements or restorative materials include zinc polycarboxylates, glass ionomers, a variety of organic polyelectrolyte adhesives as well as alginate-based impression materials. Dental cements are primarily used as luting (cementing) agents for restorations or orthodontic bands, as thermal insulators under metallic restorations, and as sealents for root canals, pits and fissures. They are also sometimes used as temporary or permanent (anterior) restorations. For further introduction to dental materials the reader is referred to standard texts [122,123]. 

Natural gums Sodium alginate Anionic 1-5 Water-dispersible 4-10 or 4-11.5 Pseudoplastic Incompatible with heavy-metal ions and sensitive to acids and ethanol in greater than 5%... 

Alginates 170,178 Alkali metal ions 206 Alkaline phosphatases 645 active site of 645 occurrence 645 Alkane(s) 382 Alkenes, hydration of 683 Alkyl shift, rearrangements with 527 Alkyl cobalt 867 Alkyl ethers 382 Alkyl cobalamms... 

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