Determination of Infinite Dilution Partial Molar Excess Enthalpies and Volumes for Some Ionic Liquid Precursors in Water and Methanol Using Tandem Flow Mixing Calorimetry and Vibrating-Tube Densimetry

Abstract

A flow mixing microcalorimetric system we developed recently was appended in this work with a vibrating tube densimeter into a tandem flow arrangement. This new combined apparatus (calo/densimeter) allows simultaneous automatic measurement of mixing enthalpies and densities of highly dilute solutions as a function of composition and, in turn, reliable determination of the solute's infinite dilution partial molar excess enthalpies H _

A combined experimental and theoretical approach to the study of hydrogen bond interaction in the binary mixture of N-methylimidazole with water

“…Commercially available MeIm was purified by repeated vacuum distillation. Obtained density of pure MeIm was 1.0309 g Á cm À1 at T = 298.15 K and was in good agreement with the corresponding literature values 1.03114 g Á cm À1 reported by Dohnal and coworkers [32]. Water used for making the aqueous solutions was distilled and deionized, and its densities over the temperature range from (288.15 to 323.15) K were in good agreement with the values given in the instruction manual of the densimeter instrument used.…”

“…Especially, in respective processes these substances often interact with aqueous media, and their solutions in water exhibit particularly complex structures and often also peculiar behavior. Although different experimental and theoretical investigations have been undertaken for these mixtures [20][21][22][23][24][25][26][27][28][29][30][31][32], it still remains a challenging task to explore their physicochemical properties of aqueous solutions and the nature of interactions between N-heterocyclic molecules with water. To date, except for the work of Dohnal and coworkers [32], no report is available in the literature on the thermodynamic properties of N-methylimidazole (MeIm) used as precursor for the synthesis of ionic liquids in aqueous solutions at different temperatures.…”

Thermodynamic properties of five biofuel-relevant compounds at infinite dilution in water

“…The measurements of mixing enthalpies and densities of highly dilute solutions were performed using a calo/densimeter described in detail previously [9]. This combined instrument integrates an isothermal mixing microcalorimeter [10] (a modified Model 4400, CSC, Provo, USA) and a vibrating-tube densimeter (Model DMA 5000, Anton Paar, Austria) into a tandem flow assembly with fully automatic control of the entire experimental sequence.…”

“…The input data for Eqs. (9) and (10), as well as the resulting values of the hydration thermal properties, are summarized in Table 4S of the Supplementary Material. As concerns methyl vinyl ketone, the K aw ðTÞ dependence was determined by fitting solely the present data as they were measured with good precision over a relatively broad temperature range of 50 K, while the conflicting literature data were considered unreliable and excluded.…”

Thermophysical properties of aqueous solutions of the 1-ethyl-3-methylimidazolium tricyanomethanide ionic liquid

“…The measurements of mixing enthalpies and densities of highly dilute solutions were performed using a calo/densimeter described in detail previously [10]. This combined instrument integrates an isothermal mixing microcalorimeter [11] (a modified Model 4400, CSC, Provo, USA) and a vibrating-tube densimeter (Model DMA 5000, Anton Paar, Austria) into a tandem flow assembly with fully automatic control of the entire experimental sequence.…”