INTERACTION OF ALGINATE WITH METAL IONS, CATIONIC SURFACTANTS AND CATIONIC DYES

摘要

Systems containing a natural polymer and metal ions in the presence or the absence of oppositely charged surfactants are considered with respect to interactions and phase behavior. Alginate is a natural linear polysaccharide extracted from marine brown algae, a copolymer of β-D-mannuronate and α-L-guluronate residues. Alginate hydrogels are made by ionically crosslinking with calcium or barium ions, in the absence or the presence of two cationic surfactants, dodecyltrimethylammonium bromide and cetyltrimethylammonium bromide. The alginate cross-link complexes can exist either as homogenous clear solutions or precipitates or as beads. The effects of some salts and sodium alginate concentrations on the properties of the gel-like membranes were investigated. The influence of the two surfactants to the domains of steep binding isotherms was also investigated. The capacity of alginate gel beads to remove some cationic dyes from water was studied.