title: Phase separation in mixtures of ionic liquids and water.
abstract: The phase separation of ionic liquids (ILs) in water is studied by laser light scattering (LLS). For the ILs with longer alkyl chains, such as [C(8)mim]BF(4) and [C(6)mim]BF(4) (mim = methylimidazolium), macroscopic phase separation occurs in the mixture with water. LLS also reveals the coexistence of the mesoscopic phase, the size of which is in the order of 100-800 nm. In aqueous mixtures of ILs with shorter alkyl chains, such as [C(4)mim]BF(4), only the mesoscopic phase exists. The mesoscopic phase can be effectively removed by filtration through a 0.22 μm filter. However, it reforms with time and can be enhanced by lowering the temperature, thus indicating that it is controlled by thermodynamics. The degree of mesoscopic phase separation can be used to evaluate the miscibility of ILs with water. This study helps to optimize the applications of ILs in related fields, as well as the recycling of ILs in the presence of water.
authors: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China.
authors: Ye
authors: Y
authors: Chen
authors: Fuyou
authors: F
authors: Ke
authors: Huaping
authors: H
authors: Wang
authors: Yumei
authors: Y
authors: Zhang
authors: Dehai
authors: D
authors: Liang
mesh_terms: D005374:Filtration; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D008027:Light; D012542:Scattering, Radiation; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: C419324:1-butyl-3-methylimidazolium tetrafluoroborate; D007093:Imidazoles; D052578:Ionic Liquids; D014867:Water