Metal Absorption Capacities of κ-Carrageenan Blends
Lead, cadmium and zinc were allowed to bind to the sulfated galactan units of κ-carrageenan by preparing a mixture of 1% κ-carrageenan in 0.1 M Pb(NO3)2 and Cd(NO3)2. and equilibrating overnight. The Pb2+ concentration in the supernatant was determined initially using potentiometric stripping analysis (PSA) but the concentration range for this application was much higher. The Pb2+ and Cd2+ concentrations were then determined by atomic absorption spectroscopy (AAS). The concentration of bound metal was calculated by substracting the amount of metal in the supernatant from the amount in the original solution. Results show that Pb2+ and Cd2+ in solution is complexed with the carrageenan. However, complexation with various carrageenan-chitosan and carrageenan-poly-N-isopropyl acrylamide (N-IPAAm) blends changes the amount of bound metal, indicating that the polyelectrolyte blend can be used to control the binding capacity of the biopolymers. AFM micrographs show some change in the topology of the various polymer systems. Thermal analysis, FTIR and GPC were also used to characterized the polymer blends.
Cuyegkeng, M., and Henares, T. (1998). Metal Absorption Capacities of κ-Carrageenan Blends. Advanced Polymers for the 21st Century: Proceedings of the DOST-JSPS Workshop on Materials and Polymer Chemistry, in E.P. Enriquez, (Ed). QC: Ateneo de Manila University ORP, 13-20 (February 1998).