Coil Dimensions of Poly(ethylene oxide) in an Ionic Liquid by Small-Angle Neutron Scattering

Aakriti Kharel, Timothy P. Lodge

Research output: Contribution to journalArticle

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Abstract

The infinite dilution radii of gyration (Rg,0) for five different molecular weights (10-250 kg/mol) of perdeuterated poly(ethylene oxide) (d-PEO) have been determined at 80 °C in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) using small-angle neutron scattering (SANS). The results establish the dependence of Rg,0 on polymer molecular weight as Rg,0 ∼ Mw0.55. An excluded volume exponent of ν ≈ 0.55 indicates that [BMIM][BF4] is a moderately good solvent and that PEO remains a flexible random coil in this ionic liquid. These results clarify the uncertainty surrounding PEO coil dimensions in this ionic liquid, as computer simulations at various levels of complexity have led to conflicting results, and prior experimental results also do not present a completely consistent picture.

Original languageEnglish (US)
Pages (from-to)8739-8744
Number of pages6
JournalMacromolecules
Volume50
Issue number21
DOIs
StatePublished - Nov 14 2017

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