Metal ion extraction from aqueous solutions is of great concern in a number of different applications. In the past, our research group was extensively interested in carrier-mediated transport through bulk liquid membranes, i.e. organic solvents separating two immiscible aqueous solutions. Many carrier molecules were synthesised in our laboratories and successfully used for the complexation and the transport of copper(II), cadmium(II), lead(II) and mercury(II) ions . In order to minimize the amounts of organic solvents employed as membrane, further researches have been directed towards alternative extraction systems, still based on the chelating properties of our carrier molecules, that is ionic liquids and sol-gel materials. We present here results on the chelating features of simple lipophilic polyamines towards Cu(II) and Hg(II) ions; the chelating agents were (i) used in water/ionic liquids biphasic systems to achieve liquid/liquid extraction processes based on imidazolium-type ionic liquids2 and (ii) immobilized on sol-gel materials to be used as stationary phases in chromatographic systems for in column metal ion extraction3. Interestingly, chelating properties of the selected molecules seemed to be deeply affected by the different employed settings.
Recognition and Complexation of Heavy Metal Ions in Ionic Liquids and Sol-Gel Materials
GERMANI, Raimondo;SAVELLI, Gianfranco;
2007
Abstract
Metal ion extraction from aqueous solutions is of great concern in a number of different applications. In the past, our research group was extensively interested in carrier-mediated transport through bulk liquid membranes, i.e. organic solvents separating two immiscible aqueous solutions. Many carrier molecules were synthesised in our laboratories and successfully used for the complexation and the transport of copper(II), cadmium(II), lead(II) and mercury(II) ions . In order to minimize the amounts of organic solvents employed as membrane, further researches have been directed towards alternative extraction systems, still based on the chelating properties of our carrier molecules, that is ionic liquids and sol-gel materials. We present here results on the chelating features of simple lipophilic polyamines towards Cu(II) and Hg(II) ions; the chelating agents were (i) used in water/ionic liquids biphasic systems to achieve liquid/liquid extraction processes based on imidazolium-type ionic liquids2 and (ii) immobilized on sol-gel materials to be used as stationary phases in chromatographic systems for in column metal ion extraction3. Interestingly, chelating properties of the selected molecules seemed to be deeply affected by the different employed settings.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
