ZIF-8-porous ionic liquids for the extraction of 2,2,3,3-tetrafluoro-1-propanol and water mixture

Abstract

The design of stable ionic liquids (ILs) has become crucial for efficient liquid–liquid extraction (LLE) of alcohol and water. Porous ionic liquids (PILs), as a special class of ILs, have attracted attention by virtue of their unique porous structure and IL characteristics. In this research, a series of zeolitic imidazolate framework-8 based porous ionic liquids (ZIF-8-PILs) were synthesized by simply mixing a solution of zeolitic imidazolate framework-8 (ZIF-8) and rationally designed ILs. The introduction of ZIF-8 resulted in a unique liquid porous structure and molecular sieve for ZIF-8-PILs. The improved extraction properties endowed ZIF-8/[Bpy][NTf₂] with more efficiency for the separation of 2,2,3,3-tetrafluoro-1-propanol (TFP) and water with 88.1% TFP extraction rate and steady reuse. The excellent extraction performance of ZIF-8-PILs is discussed in relation to their textural property and unique intermolecular interaction.