EXTRACTION OF NAPHTHALENE BY BLOCK-COPOLYMER SURFACTANTS IMMOBILIZED IN POLYMERIC HYDROGELS

Gel/micelle materials, comprising hydrogels containing block copolymer micelles, have the potential to be very useful in a variety of extrac tion and controlled release applications. It is demonstrated that bloc k copolymer surfactants can be immobilized in calcium alginate gels an d that the resulting composite material preferentially solubilizes the model hydrophobic solute naphthalene. Five different polyethylene oxi de-polypropylene oxide-polyethylene oxide triblock copolymer surfactan ts are considered, and the qualitatively different properties exhibite d are interpreted in light of the properties of these surfactants in s olution. Alginate gel concentrations of 22.5 and 52.5 g/L and surfacta nt concentrations ranging from 20.4 to 136 g/L are considered. The dat a indicate that micelles can be permanently immobilized for purposes o f extraction or controlled release and that the extent of solute uptak e or release can be altered by varying gel and surfactant concentratio n and the type of surfactant employed.