Investigation on the Interactions of Poly(ethylene oxide) and Ionic Liquid 1-Butyl-3-methyl-imidazolium Bromide by Viscosity and Spectroscopy

Abstract

In this research, the solution of poly­(ethylene oxide) in binary mixtures of water and ionic liquid, 1-butyl-3-methyl imidazolium bromide, were studied via spectroscopic and viscometric at the temperature range of 288.15–313.15 K. Also, the effects of ionic liquid, 1-butyl-3-methyl imidazolium bromide, on the thermodynamic parameters of dilute aqueous solutions of poly­(ethylene oxide), such as polymer–solvent interaction parameter, theta temperature, the heat of dilution parameter, and the entropy of dilution parameter were investigated. Our data indicate that the thermodynamic quality of water for poly­(ethylene oxide) is reduced by the addition of 1-butyl-3-methyl imidazolium bromide and increasing temperature. The flow activation energy was calculated and correlated in terms of polymer concentration. The sign of initial slope of the activation energy versus polymer concentration at zero concentration reveals that thermodynamic quality of IL aqueous solutions is reduced by increasing temperature. The type of interactions between poly­(ethylene oxide) and 1-butyl-3-methyl imidazolium bromide was studied by Fourier transform infrared (FT-IR) and UV–vis methods. The existence of hydrogen bonding between the imidazolium cation and the oxygen atom of poly­(ethylene oxide) was confirmed by the results of FT-IR and UV–vis spectroscopies.

Healable Ionoelastomer Designed from Polymeric Ionic Liquid and Vitrimer Chemistry

“…It demonstrates that the choice of polar dangling chains such as PEG is critical in the enhancement of ionic mobility. Indeed, the existence of hydrogen bonding between the imidazolium group and PEO has been reported. , This interaction could allow better the dissociation of the 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI) ionic pair by hindering the cation and creating a polar medium to promote the ionic movement.…”

“…Indeed, the existence of hydrogen bonding between the imidazolium group and PEO has been reported. 62,63 This interaction could allow better the dissociation of the 1-ethyl-3methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI) ionic pair by hindering the cation and creating a polar medium to promote the ionic movement. VTF parameters of the synthesized ionoelastomers were extrapolated, with R 2 fit values above 0.99, confirming that the movement of ions was correlated to those of polymer chains.…”

Structural Reorganization of Imidazolium Ionic Liquids Induced by Pressure-Enhanced Ionic Liquid—Polyethylene Oxide Interactions

“…A population of PEO atoms may be located around the long hexyl chain of [HMIM] + under high pressures. The studies of the 1-alkyl-3-methylimidazolium bromide ILs indicate that some hydrogen bonds between the cation and Br - are replaced by hydrogen bonding between the imidazolium and oxygen atom of PEO upon the addition of PEO to the ILs [ 27 , 28 ]. Furthermore, it has been concluded that for the 1-alkyl-3-methylimidazolium ILs, PEO can solvate the large imidazolium moieties with less stringent local modification via the van der Waals interaction with the PEO chains [ 4 ].…”

“…The linear polymer PEO is generally water-soluble owing to the presence of the ethylene oxide group, and the oxygen atoms of PEO are promising candidates as hydrogen-bond acceptors (HBAs) [ 20 , 27 , 28 ]. Researchers have shown that some associations between IL cations and anions may be substituted by the interactions of IL cations and PEO oxygen atoms upon mixing PEO with ILs [ 27 , 28 ].…”

“…The linear polymer PEO is generally water-soluble owing to the presence of the ethylene oxide group, and the oxygen atoms of PEO are promising candidates as hydrogen-bond acceptors (HBAs) [ 20 , 27 , 28 ]. Researchers have shown that some associations between IL cations and anions may be substituted by the interactions of IL cations and PEO oxygen atoms upon mixing PEO with ILs [ 27 , 28 ]. Using molecular dynamics simulations, it has been determined that the distances between the imidazolium rings of ILs and oxygen atoms of PEO are slightly shorter than those of the cations and anions in the IL polymer electrolytes [ 4 , 20 ].…”