Density scaling of structure and dynamics of an ionic liquid
Artikel i vetenskaplig tidskrift, 2020

Room temperature ionic liquids are salts with low melting points achieved by employing bulky and asymmetrical ions. The molecular design leads to apolar and polar parts as well as the presence of competing Coulomb and van der Waals interactions giving rise to nano-scale structure, e.g. charge ordering. In this paper we address the question of how these nano-scale structures influence transport properties and dynamics on different timescales. We apply pressure and temperature as control parameters and investigate the structure factor, charge transport, microscopic alpha relaxation and phonon dynamics in the phase diagram of an ionic liquid. Including viscosity and self diffusion data from literature we find that all the dynamic and transport variables studied follow the same density scaling, i.e. they all depend on the scaling variable Γ = ργ/T, with γ = 2.8. The molecular nearest neighbor structure is found to follow a density scaling identical to that of the dynamics, while this is not the case for the charge ordering, indicating that the charge ordering has little influence on the investigated dynamics.

Författare

Henriette Wase Hansen

Chalmers, Fysik, Materialfysik

Roskilde Universitet (RUC)

Institut Laue-Langevin

Filippa Lundin

Chalmers, Fysik, Materialfysik

Karolina Adrjanowicz

University of Silesia in Katowice

Bernhard Frick

Institut Laue-Langevin

Aleksandar Matic

Chalmers, Fysik, Materialfysik

Kristine Niss

Roskilde Universitet (RUC)

Physical Chemistry Chemical Physics

1463-9076 (ISSN) 1463-9084 (eISSN)

Vol. 22 25 14169-14176

Sveriges Neutronforskarskola - SwedNESS

Stiftelsen för Strategisk forskning (SSF), 2017-01-01 -- 2020-12-31.

Stiftelsen för Strategisk forskning (SSF), 2016-07-01 -- 2021-06-30.

Ämneskategorier

Fysikalisk kemi

Atom- och molekylfysik och optik

DOI

10.1039/d0cp01258k

PubMed

32609117

Mer information

Senast uppdaterat

2020-09-09