Enhancing extraction ability by rational design of phosphoryl functionalized ionic liquids and mechanistic investigation on neodymium(III) extraction

王君平，赵洁莹，冯达，康鑫淳，孙云雨，赵玲玲，梁洪泽

Faculty of Materials Science and Chemical Engineering Ningbo University

摘 要：Four ionic liquids（ILs）: 3-（diethoxyphosphoryl）propyl triphenylphosphinium hexafluorophosphate [Ph3PC3P（OEt）2][PF6]（IL-1）, 3-（ethoxyphenylphosphoryl）propyl triphenylphosphinium hexafluorophosphate [Ph3PC3PPh（OEt）][PF6]（IL-2）, 3-（diphenylphosphoryl）propyl triphenylphosphinium hexafluorophosphate [Ph3PC3P（Ph）2][PF6]（IL-3）, and 3-（diethoxyphosphoryl）propyl triphenylphosphinium bis（trifluoromethanesulfonyl）imide [Ph3PC3P（OEt）2][NTf2]（IL-4） were synthesized and characterized by IR and 31 P, 1H, 13 C NMR spectroscopy. The liquid-liquid extraction of neodymium（III） by these phosphorus functionalized ionic liquids（PFILs） diluted with common room temperature ionic liquid 1-hexyl-3-methylimidazolium bis（trifluoromethylsulfonyl）imide [C6mim][NTf2] was studied. The extraction percentage of Nd（III） was measured as a function of various parameters, such as the initial p H of aqueous phase, equilibrium time, temperature, and concentration of PFIL extractant. The influence of the nature of diluents and salting-out reagents on extraction was also investigated. The results indicated that the extraction process was exothermical and the extraction percentage of Nd（III） by IL-1 was the highest among the PFILs investigated. A possible metal complexation mechanism was proposed for the present PFIL/IL extraction system. And the loaded Nd（III） ions by PFIL could be stripped completely from the ionic liquid phase by 1 mol/L nitric acid.

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