“…The distilled properties of these ILs would attract more attention and expand the application of ILs in new fields, for example, in separating the rare earth elements (REEs). 33 Because of the wide applications of REEs in many hi-tech fields, such as lamp phosphors, rechargeable batteries, permanent magnets, catalysis and the ceramic industry, separation technologies are more and more important because REEs share similar properties, thus tending to exist together naturally. 34 Although acidic organophosphorous, 35 functional ILs, 36 and amine extractants have been used for REEs separation, 37 they were of high cost and difficult to be recycled.…”