title: Conformation of poly(ethylene oxide) dissolved in the solvate ionic liquid [Li(G4)]TFSI.
abstract: The conformation of 38 kDa PEO in a solvate ionic liquid (SIL), lithium tetraglyme bis(trifluoromethane-sulfonyl)amide ([Li(G4)]TFSI) from dilute to concentrated solution regimes has been determined by small angle neutron scattering and rheology. SANS analysis reveals that [Li(G4)]TFSI is better than a theta solvent (theta-good) for PEO. The variation of the radius of gyration (Rg) and viscosity as a function of polymer concentration allow the overlap concentrations, c* and c**, to be identified at 13 mg mL(-1) and 50 mg mL(-1), respectively, which are similar to values reported previously for conventional ionic liquids. Unlike water and conventional ionic liquids, [Li(G4)]TFSI cannot form hydrogen bonds with PEO. Thermal gravimetric analysis indicates that the solvation of PEO by [Li(G4)]TFSI is a consequence of PEO forming coordinate bonds with the lithium by displacing the anion, but without displacing the glyme molecule.
authors.affiliation: Newcastle Institute for Energy and Resources, The University of Newcastle, Callaghan, NSW, Australia. rob.atkin@newcastle.edu.au.
authors.forename: Zhengfei
authors.initials: Z
authors.lastname: Chen
authors.forename: Paul A
authors.initials: PA
authors.lastname: FitzGerald
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Warr
authors.forename: Rob
authors.initials: R
authors.lastname: Atkin