Journal article
Relationship between the Relaxation of Ionic Liquid Structural Motifs and That of the Shear Viscosity
The journal of physical chemistry. B, Vol.125(23), pp.6264-6271
06/17/2021
DOI: 10.1021/acs.jpcb.1c03105
PMCID: PMC8279556
PMID: 34097825
Appears in UI Libraries Support Open Access
Abstract
In a set of recent articles, we have highlighted that friction is highly inhomogeneous in a typical ionic liquid (IL) with charge networks that are stiff and charge-depleted regions that are soft. This has consequences not only for the dynamics of ILs but also for the transport properties of solutes dissolved in them. In this article, we explore whether the family of alkylimidazolium ILs coupled with bis(trifluoromethylsulfonyl)imide (with similar Coulombic interactions but different alkyl tails), when dynamically “equalized” by having a similar shear viscosity, display q-dependent structural relaxation time scales that are the same across the family. Our results show that this is not the case, and in fact, the relaxation of in-network charge alternation appears to be significantly affected by the presence of separate polar and apolar domains. However, we also find that if one was to assign weight factors to the relaxation of the structural motifs, charge alternation always contributes about the same amount (between 62.1 and 66.3%) across systems to the running integral of the stress tensor correlation function from which the shear viscosity is derived. Adjacency correlations between positive and negative moieties also contribute an identical amount if a prepeak is not present (about 38%) and a slightly smaller amount (about 28%) when intermediate range order exists. The prepeak only contributes about 6% to viscoelastic relaxation, highlighting that the dynamics of the smaller scale motifs is the most important.
Details
- Title: Subtitle
- Relationship between the Relaxation of Ionic Liquid Structural Motifs and That of the Shear Viscosity
- Creators
- Weththasinghage D Amith - University of IowaJuan C Araque - Benedictine CollegeClaudio J Margulis - University of Iowa
- Resource Type
- Journal article
- Publication Details
- The journal of physical chemistry. B, Vol.125(23), pp.6264-6271
- DOI
- 10.1021/acs.jpcb.1c03105
- PMID
- 34097825
- PMCID
- PMC8279556
- NLM abbreviation
- J Phys Chem B
- ISSN
- 1520-6106
- eISSN
- 1520-5207
- Publisher
- American Chemical Society
- Grant note
- DOI: 10.13039/100000001, name: National Science Foundation, award: CHE 1954358
- Language
- English
- Date published
- 06/17/2021
- Academic Unit
- Chemistry
- Record Identifier
- 9984216675302771
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