title: Proton Transport in Imidazoles: Unraveling the Role of Supramolecular Structure.
abstract: The impact of supramolecular hydrogen bonded networks on dynamics and charge transport in 2-ethyl-4-methylimidazole (2E4MIm), a model proton-conducting system, is investigated by broadband dielectric spectroscopy, depolarized dynamic light scattering, viscometry, and calorimetry. It is observed that the slow, Debye-like relaxation reflecting the supramolecular structure in neat 2E4MIm is eliminated upon the addition of minute amounts of levulinic acid. This is attributed to the dissociation of imidazole molecules and the breaking down of hydrogen-bonded chains, which leads to a 10-fold enhancement of ionic conductivity.
authors.forename: Tyler
authors.initials: T
authors.lastname: Cosby
authors.forename: Adam
authors.initials: A
authors.lastname: Holt
authors.affiliation: Department of Materials Science and Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Griffin
authors.affiliation: Center for Nanophase Materials Science, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Wang
authors.forename: Joshua
authors.initials: J
authors.lastname: Sangoro
keywords: Debye relaxation; Grotthuss mechanism; hydrogen-bonding; imidazole; proton conducting liquid; supramolecular