Aqueous solutions of [EMIM] 1,1,2,2-tetrafluoroethanesulfonate and [EMIM] trifluoromethanesulfonate: a thermodynamic study

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F18%3A43913458" target="_blank" >RIV/60461373:22340/18:43913458 - isvavai.cz</a>

Result on the web

<a href="http://www.sciencedirect.com/science/article/pii/S002196141730455X" target="_blank" >http://www.sciencedirect.com/science/article/pii/S002196141730455X</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jct.2017.12.019" target="_blank" >10.1016/j.jct.2017.12.019</a>

Result language

angličtina

Original language name

Aqueous solutions of [EMIM] 1,1,2,2-tetrafluoroethanesulfonate and [EMIM] trifluoromethanesulfonate: a thermodynamic study

Original language description

While ionic liquids (ILs) based on a trifluoromethanesulfonate ([OTF]–) anion and their mixtures with other compounds have been relatively well explored, the information about structurally similar 1,1,2,2-tetrafluoroethanesulfonate-based ([TFES]–) ILs is either very scarce or, as in the case of their mixtures with water, totally lacking. We herein thus present a broad thermodynamic characterization of aqueous solutions of [EMIM][TFES] and [EMIM][OTF], with the study of aqueous solutions of the latter serving as a benchmark. First, the peculiar solid-liquid phase transition behavior of the neat [EMIM][TFES] was examined and its density was determined over a temperature range encompassing both the subcooled and the stable liquid. For the aqueous solutions of the two ILs, we performed extensive measurements of water activity (a_w) across the entire composition range, mixing enthalpy and density specifically in the highly dilute IL region, and the solution freezing temperatures at water mole fractions greater than 0.6. The ample a_w data were fitted (i) by a two-step procedure and (ii) simultaneously with the excess enthalpy data using an extended NRTL-type model. The latter approach to the global description of energetics of the systems is preferred for its handiness in practical calculations. We duly proved its reliability in extrapolation and/or prediction against experimental data on various properties, among others, SLE. The analysis of volumetric data by the Redlich-Meyer equation allowed us to obtain accurate values of infinite dilution partial molar volumes of the ILs and revealed the nature of their hydration as rather hydrophobic. The solution behavior of the systems studied was found to be essentially non-ideal: their small S-shaped excess Gibbs energy actually results from the compensation of their large positive excess enthalpy and entropy.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10403 - Physical chemistry

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Chemical Thermodynamics

ISSN

0021-9614

e-ISSN

—

Volume of the periodical

119

Issue of the periodical within the volume

April

Country of publishing house

GB - UNITED KINGDOM

Number of pages

13

Pages from-to

114-126

UT code for WoS article

000425191700012

EID of the result in the Scopus database

2-s2.0-85042513014