Experimental Evidence for a State-Point-Independent Density-Scaling Exponent in Ionic Liquids

Z Wojnarowska; M Musiał; M Dzida; M Paluch

doi:10.1103/PhysRevLett.123.125702

Experimental Evidence for a State-Point-Independent Density-Scaling Exponent in Ionic Liquids

Phys Rev Lett. 2019 Sep 20;123(12):125702. doi: 10.1103/PhysRevLett.123.125702.

Authors

Z Wojnarowska¹, M Musiał², M Dzida², M Paluch¹

Affiliations

¹ Institute of Physics, University of Silesia in Katowice, SMCEBI, 75 Pulku Piechoty 1A, Chorzow 41-500, Poland.
² Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, Katowice 40-006, Poland.

PMID: 31633969
DOI: 10.1103/PhysRevLett.123.125702

Abstract

This Letter addresses a fundamental issue of condensed-matter physics, which is the validity of the density-scaling concept. For this purpose, the ambient and high-pressure conductivity measurements of two selected ionic liquids (ILs), with the different contribution of H-bonding interactions, were performed in the dynamic range of 13 orders of magnitude and corresponding to the density changes as large as 20%. All experimental data obtained within one compound are shown to superimpose each other when plotted as a function of ρ^{γ}/T. These results clearly show that for studied ILs the scaling exponent is a state-point-independent parameter that is in odds with the recent findings for van der Waals liquid [Sanz et al., Phys. Rev. Lett. 122, 055501 (2019)PRLTAO0031-900710.1103/PhysRevLett.122.055501].