Effect of ionic liquids on the aggregation behavior of PEO-PPO-PEO block copolymers in aqueous solution.
Effect of 1-butyl-3-methyl-imidazolium bromide (BmimBr) on the aggregation behavior of PEO-PPO-PEO Pluronic P104 aqueous solution was studied by Fourier transform infrared (FTIR) spectroscopy, freeze fracture transmission electron microscopy (FF-TEM), dynamic light scattering (DLS), and NMR spectroscopy. When the BmimBr concentration was below 1.232 mol/L, the critical micelle temperature (CMT) of Pluronic P104 remained constant, while the size of micelles increased with increasing the BmimBr concentration; above this concentration, the CMT of Pluronic P104 decreased abruptly, and bigger clusters of BmimBr were formed. The selective nuclear Overhauser effect (NOE) spectrum indicates that the PO block of the P104 interacts with the butyl group of the Bmim+ cation by hydrophobic interaction. It suggests that when the concentration of BmimBr is below 1.232 mol/L, there are P104 micelles in the aqueous solution with BmimBr embedding to the micellar core, while above this concentration, P104 micelles and BmimBr clusters coexist in the system.
Zheng
Lily
L
Laboratory of Separation Science and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing 100080, China.
Guo
Chen
C
Wang
Jing
J
Liang
Xiangfeng
X
Chen
Shu
S
Ma
Junhe
J
Yang
Bin
B
Jiang
Yangyang
Y
Liu
Huizhou
H
D006842:Hydrocarbons, Brominated / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D020442:Poloxamer / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D011409:Propylene Glycols / Q000737:chemistry*; D012542:Scattering, Radiation; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry*
D006842:Hydrocarbons, Brominated; D007093:Imidazoles; D052578:Ionic Liquids; D008823:Micelles; C116176:PEO-PPO-PEO; D011409:Propylene Glycols; D013501:Surface-Active Agents; D014867:Water; D020442:Poloxamer; D011092:Polyethylene Glycols