Thermodynamic properties of aqueous solutions of [EMIM] thiocyanate and [EMIM] dicyanamide

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F17%3A43913456" target="_blank" >RIV/60461373:22340/17:43913456 - isvavai.cz</a>

Result on the web

<a href="http://ac.els-cdn.com/S0021961416304050/1-s2.0-S0021961416304050-main.pdf?_tid=63bb7728-f833-11e6-81f7-00000aab0f6b&acdnat=1487681208_a2755d19d71303cb1cf64e157e6f8114" target="_blank" >http://ac.els-cdn.com/S0021961416304050/1-s2.0-S0021961416304050-main.pdf?_tid=63bb7728-f833-11e6-81f7-00000aab0f6b&acdnat=1487681208_a2755d19d71303cb1cf64e157e6f8114</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jct.2016.12.008" target="_blank" >10.1016/j.jct.2016.12.008</a>

Result language

angličtina

Original language name

Thermodynamic properties of aqueous solutions of [EMIM] thiocyanate and [EMIM] dicyanamide

Original language description

Thermodynamic behavior of aqueous solutions of two ionic liquids (ILs), [EMIM][SCN] and [EMIM][DCA], was thoroughly characterized. Vapor?liquid equilibria (water activity), mixing enthalpy, density, and viscosity were systematically measured in the entire composition range and/or specifically in the highly dilute IL region, as a function of temperature in the range from (288.15 to 318.15) K. Pertinent information available in the literature was gathered and critically examined. Data on system energetics, measured in this work and selected from the literature, were simultaneously correlated with an NRTL-type model. Despite complicated courses of excess energetic functions, their compact, thermodynamically consistent and adequate representation was achieved and the model description was proved to provide reasonable extrapolations. Excess volumes (positive) and viscosity deviations (negative) as functions of composition and temperature were correlated with Padé approximants with T-dependent parameters yielding adequate representation of data even for the M-shaped curves encountered for the excess volume of (water + [EMIM][SCN]). The aqueous solutions of [EMIM][SCN] and [EMIM][DCA] were found to exhibit a closely similar energetic behavior. Both systems display large negative excess Gibbs energy and S-shaped excess enthalpy and excess heat capacity which are positive in the IL dilute region and change to negative and close-to-zero, respectively, as the IL content increases. The inferred excess entropy is markedly positive, reflecting vast disorganization of nano-scale structures upon mixing the ILs with water. A detailed inspection of the energetic functions of the two systems revealed consistently more positive values for [EMIM][SCN] indicating that [DCA]? is slightly more hydrophilic anion than [SCN]?. Comparison to [EMIM][tricaynomethanide] studied previously showed that [DCA]? and [SCN]? are considerably more hydrophilic than [TCM]?.

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

—

OECD FORD branch

10403 - Physical chemistry

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

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

106

Issue of the periodical within the volume

March

Country of publishing house

GB - UNITED KINGDOM

Number of pages

14

Pages from-to

262-275

UT code for WoS article

000392352900029

EID of the result in the Scopus database

2-s2.0-85006710938