A green extraction process for the selective recovery of Sc(iii) based on hydrophobic betaine derivative ionic liquids.

The efficient extraction recovery of scandium (Sc(iii)) is crucial for its application in high-end technology. Two novel hydrophobic carboxylic acid ionic liquids (ILs), namely, [lauryl betaine][bis(trifluoromethanesulphonyl)imide] ([Laur][TfN]) and [cocamidopropyl betaine][bis(trifluoromethanesulphonyl)imide] ([Coca][TfN]), were synthesized using two inexpensive amphoteric surfactants as cation sources. [Laur][TfN] (257 °C) and [Coca][TfN] (251 °C) exhibited good thermal stability and strong hydrophobicity.