- Title
- Structural effect of glyme-Li⁺ salt solvate ionic liquids on the conformation of poly(ethylene oxide)
- Creator
- Chen, Zhengfei; McDonald, Samila; Fitzgerald, Paul A.; Warr, Gregory G.; Atkin, Rob
- Relation
- ARC
- Relation
- Physical Chemistry Chemical Physics Vol. 18, Issue 22, p. 14894-14903
- Publisher Link
- http://dx.doi.org/10.1039/c6cp00919k
- Publisher
- Royal Society of Chemistry
- Resource Type
- journal article
- Date
- 2016
- Description
- The conformation of 36 kDa polyethylene oxide (PEO) dissolved in three glyme–Li⁺ solvate ionic liquids (SILs) has been investigated by small angle neutron scattering (SANS) and rheology as a function of concentration and compared to a previously studied SIL. The solvent quality of a SIL for PEO can be tuned by changing the glyme length and anion type. Thermogravimetric analysis (TGA) reveals that PEO is dissolved in the SILs through Li⁺–PEO coordinate bonds. All SILs (lithium triglyme bis(trifluoromethanesulfonyl)imide ([Li(G3)]TFSI), lithium tetraglyme bis(pentafluoroethanesulfonyl)imide ([Li(G4)]BETI), lithium tetraglyme perchlorate ([Li(G4)]ClO₄) and the recently published [Li(G4)]TFSI) are found to be moderately good solvents for PEO but solvent quality decreases in the order [Li(G4)]TFSI ∼ [Li(G4)]BETI > [Li(G4)]ClO₄ > [Li(G3)]TFSI due to decreased availability of Li⁺ for PEO coordination. For the same glyme length, the solvent qualities of SILs with TFSI⁻ and BETI⁻ anions ([Li(G4)]TFSI and [Li(G4)]BETI) are very similar because they weakly coordinate with Li⁺, which facilitates Li⁺–PEO interactions. [Li(G4)]ClO₄ presents a poorer solvent environment for PEO than [Li(G4)]BETI because ClO₄⁻ binds more strongly to Li⁺ and thereby hinders interactions with PEO. [Li(G3)]TFSI is the poorest PEO solvent of these SILs because G3 binds more strongly to Li⁺ than G4. Rheological and radius of gyration (Rg) data as a function of PEO concentration show that the PEO overlap concentrations, c* and c**, are similar in the three SILs.
- Subject
- glyme–Li⁺; ionic liquids; poly(ethylene oxide)
- Identifier
- http://hdl.handle.net/1959.13/1338029
- Identifier
- uon:27922
- Identifier
- ISSN:1463-9076
- Language
- eng
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