title: Using UCST Ionic Liquid as a Draw Solute in Forward Osmosis to Treat High-Salinity Water.
abstract: The concept of using a thermoresponsive ionic liquid (IL) with an upper critical solution temperature (UCST) as a draw solute in forward osmosis (FO) was successfully demonstrated here experimentally. A 3.2 M solution of protonated betaine bis(trifluoromethylsulfonyl)imide ([Hbet][Tf2N]) was obtained by heating and maintaining the temperature above 56 °C. This solution successfully drew water from high-salinity water up to 3.0 M through FO. When the IL solution cooled to room temperature, it spontaneously separated into a water-rich phase and an IL-rich phase: the water-rich phase was the produced water that contained a low IL concentration, and the IL-rich phase could be used directly as the draw solution in the next cycle of the FO process. The thermal stability, thermal-responsive solubility, and UV-vis absorption spectra of the IL were also studied in detail.
authors.affiliation: Division of Physical Science and Engineering, King Abdullah University of Science and Technology , Thuwal, Saudi Arabia , 23955-6900.
authors.forename: Yujiang
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: Division of Physical Science and Engineering, King Abdullah University of Science and Technology , Thuwal, Saudi Arabia , 23955-6900.
authors.forename: Xiaoshuang
authors.initials: X
authors.lastname: Feng
authors.affiliation: Division of Physical Science and Engineering, King Abdullah University of Science and Technology , Thuwal, Saudi Arabia , 23955-6900.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Division of Physical Science and Engineering, King Abdullah University of Science and Technology , Thuwal, Saudi Arabia , 23955-6900.
authors.forename: Xinbo
authors.initials: X
authors.lastname: Wang
authors.affiliation: Division of Physical Science and Engineering, King Abdullah University of Science and Technology , Thuwal, Saudi Arabia , 23955-6900.
authors.forename: Kuo-Wei
authors.initials: KW
authors.lastname: Huang
authors.affiliation: Division of Physical Science and Engineering, King Abdullah University of Science and Technology , Thuwal, Saudi Arabia , 23955-6900.
authors.forename: Yves
authors.initials: Y
authors.lastname: Gnanou
authors.affiliation: Division of Physical Science and Engineering, King Abdullah University of Science and Technology , Thuwal, Saudi Arabia , 23955-6900.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Lai
mesh_terms: D006361:Heating; D052578:Ionic Liquids / Q000737:chemistry*; D009995:Osmosis; D054712:Salinity; D012995:Solubility; D012996:Solutions / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D014867:Water / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D052578:Ionic Liquids; D012996:Solutions; D014867:Water