Thermodynamic Properties of 1-Butyl-3-methylpyridinium Tetrafluoroborate and Its Mixtures with Water and Alkanols

Abstract

In this article, we study the behavior of an ionic liquid (IL) derived from pyridinium, 1-butyl-3-methylpyridinium tetrafluoroborate [b3mpy][BF4], in mixtures with water and with the first alkanols of the series from methanol to butan-1-ol, at the temperatures of (298.15 and 318.15) K. First, the miscibility regions with the alkanols were established at these two temperatures, determining experimentally the liquid−liquid equilibria and the upper critical solution temperature (UCST) for each binary mixture, confirming the quasiexponential variation of the UCST with the alkanol chain. The enthalpies were determined experimentally with a newly designed calorimetric cell, and the excess molar volumes were determined from densities, at (298.15 and 318.15) K. In all cases, the are positive with (d /dT)p > 0, whereas the are negative for mixtures with alkanols but positive for the mixture of IL + water. The thermal coefficient (d /dT)p > 0 was also positive in all cases. All data were correlated with a suitable polynomial equation, and the area and volume parameters of [b3mpy][BF4] were calculated. Finally, we give an interpretation of the results and of the behavior of the mixtures.

Thermodynamic study of (alkyl esters+α,ω-alkyl dihalides) VI. and for 20 binary mixtures {xCu−1H2u−1CO2(CH2)3CH3+(1−x)α,ω-BrCH2(CH2)v−2CH2Br}, where u=1 to 5, α=1, and v=ω=2 to 6

“…At least from a qualitative perspective, the existence of opposing effects, exo/ endothermic in the H E m and expansion/contraction in the V E m , are the result of different interactional contributions mentioned previously, and clearly vary in relation to the chain length of the compounds constituting the binary mixture, as explained below. In general, the behaviour of these mixtures is as expected from the results obtained in the series of papers [1,2,5,9,10], in which they have been discussed to some length. For this reason, here we only mention the effects that are specific to this type of mixture.…”

“…In another stage of the research, a procedure was applied that had been used previously with dihalides [10,14], in which the interaction parameters were dependent on the chain length of the interacting compounds. To carry out this method, first a preliminary study was conducted, by calculating the most suitable parameters for each of the mixtures.…”

Liquid–Liquid Equilibria in Binary Solutions Formed by [Pyridinium-Derived][F4B] Ionic Liquids and Alkanols: New Experimental Data and Validation of a Multiparametric Model for Correlating LLE Data

“…To calculate the parameters of the model chosen for the activity coefficients, the criteria described in the literature 11 have 4 ] + pentan-1-ol, indicating the isothermal curve (solid black line) at 331.08 K and the red line on the surface, which is generated by the set of points corresponding to the shaft between that surface and the tangent lines under isothermal conditions. The projection on the TÀx IL plane of the 3D trajectory creates a curve of the conjugate compositions of LLE for the binary indicated in Figure 3.…”

“…More specifically, some pyridine derivatives (such as those used in this work) have produced good results in certain applications, such as sulfur extracting agents, 1 lubricants, 2 and chemical reactions. 3 Our research group has worked with three isomeric substances having a common nucleus of a pyridine derivative, [butyl-Xmethylpyridinium] (X = 2, 3,4) [tetrafluoroborate], 4À6 and other nonisomeric [butylpyridinium][tetrafluoroborate], 7 using water and several alkanols (methanol to pentanol) as solvents. For some of these mixtures, the miscibility capacities are known; however, these studies are incomplete, because the initial working project included a greater number of alkanols, from methanol to decanol, with the limitations imposed by the variable temperature in experiments carried out at atmospheric pressure.…”

Excess properties for binary systems ionic liquid+ethanol: Experimental results and theoretical description using the ERAS model

“…In this context, the study of binary RTIL + alcohol systems has received great attention. Although phase equilibria and volumetric properties of such mixtures have been extensively determined [26][27][28][29][30][31][32][33][34][35], there are few works devoted to the thermal properties of these systems [33][34][35], which are essential for a complete description of their thermodynamic behavior.…”