화학공학소재연구정보센터
Separation Science and Technology, Vol.50, No.1, 38-44, 2015
Extraction of Metal Ions with Task Specific Ionic Liquids: Influence of a Coordinating Anion
Hydrophobic ionic liquids (ILs) were generated by association between a cationic ester derivative of betaine and bis(trifluoromethylsulfonyl)imide (Tf2N-) or dicyanamide (Dca(-)) anions. Extraction of Cu(II), Ni(II), Pb(II), and Cd(II) from water was performed with these ILs at room temperature. The use of Dca(-) anion greatly enhances the extraction efficiency of IL phase towards metal ions extraction. The metal could be back-extracted from the ionic liquid phase with aqueous EDTA solutions. The metal extractability of the ionic liquid after the back-extraction is equivalent to that of the fresh mixture showing that ionic liquid can be reused for several extraction and back-extraction cycles.