Excess Enthalpies of Mixing, Effect of Temperature and Composition on the Density, and Viscosity and Thermodynamic Properties of Binary Systems of {Ammonium-Based Ionic Liquid + Alkanediol}

2014 ◽  
Vol 118 (44) ◽  
pp. 12692-12705 ◽  
Author(s):  
Urszula Domańska ◽  
Paulina Papis ◽  
Jerzy Szydłowski ◽  
Marta Królikowska ◽  
Marek Królikowski
Author(s):  
N. Kotova ◽  
N. Usenko ◽  
N. Golovata

The features of the component interaction in liquid alloys of ternary Al-Ge-3d-Me systems (Me = Mn, Fe, Ni, Cu) are described. A joint analysis of the concentration dependences of the enthalpies of mixing of liquid alloys previously obtained by the authors via high-temperature calorimetry, and also of the phase diagrams of the constituent binary systems was carried out. The relationship between the enthalpy values and the type of short-range ordering in liquid alloys of the studied systems was established. The visual similarity of the topology of the projections of ΔmH isolines of the Al-Ge-Fe (Ni, Cu) liquid alloys and a completely different course of the isolines of the enthalpies of mixing for the liquid Al-Ge-Mn alloys are established. The changes in the absolute values of the ΔmHmin from system to system are observed. The enthalpies are approximately the same for the Al-Ge-Mn and Al-Ge-Fe systems (about -20 kJ⋅mol-1), they increase significantly from Al-Ge-Fe to Al-Ge-Ni (-50 kJ⋅mol-1), and then decrease substantially towards the Al-Ge-Cu system (-15 kJ⋅mol-1). For the Al-Ge-Mn (Fe, Ni, Cu) liquid alloys the lines of extreme interaction are located near the 3d-corner of the concentration triangle. These lines connect the compositions of the most stable intermetallic compounds in binary Al(Ge)-Mn(Fe, Ni, Cu) systems. It has been shown that the thermodynamic properties of Al-Ge-Fe (Ni, Cu) liquid alloys are mainly determined by the pair interaction of the components of the constituent binary Al-Fe(Ni, Cu) and Ge-Fe(Ni, Cu) systems, the influence of Al-Fe(Ni, Cu) systems being prevailed. For the Al-Ge-Mn system, the interaction of components in the Ge-Mn binary system gives the main contribution to the thermodynamic properties of the ternary system. The Al-Ge-Mn (Fe, Cu) systems are characterized by significantly lower absolute values of the heats of alloy formation compared to the Al-Ge-Ni one. The specified characteristics of component interaction in the ternary systems under consideration and different values of the enthalpies of mixing are determined by the peculiarities and regular changes of the electronic structure of 3d metals across the 3d series from Mn to Cu.


2017 ◽  
Author(s):  
◽  
Sangeeta Singh

The thermodynamic properties of mixtures involving ionic liquids (ILs) with organic acid (acetic acid or propanoic acid) or acetonitrile at different temperatures were determined. The ILs used were imidazolium-based: 1-ethyl-3-methylimidazolium ethyl sulphate [EMIM]+[EtSO4]-, 1-butyl- 3-methylimidazolium thiocyanate [BMIM]+[SCN]- and 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([BMIM]+[Tf2N]-. The ternary excess molar volume (V E ), isentropic compressibility (ks) and deviation in isentropic compressibility ( ks123 ) were determined for four ternary liquid mixtures of {[EMIM]+[EtSO4]- or [BMIM]+[SCN]− + acetic or propionic acid + acetonitrile} at different temperatures (293.15, 298.15, 303.15, 308.15 and 313.15) K and at a pressure of 0.1 MPa with aid of the experimental density (ρ), speed of sound (u) data. The calculated data were correlated by using the Cibulka equation with the help of Redlich–Kister parameters obtained from fitting the Redlich–Kister equation for the corresponding binary systems. Furthermore, the density and speed of sound were also measured for eight corresponding binary systems at the same experimental conditions. The binary excess molar volume, isentropic compressibility and deviation in isentropic compressibility were also calculated for measured systems and fitted to the Redlich–Kister equation to obtain the Redlich–Kister parameters as well as to check the accuracy of measured data which were used to correlated experimental data using Cibulka equation. These results were discussed, in terms of how the sign and magnitude of thermodynamic functions were influenced by the addition of a third component to liquid systems. Also, the possible molecular and pair-wise interactions between component molecules and the effect of temperature on the thermophysical and thermodynamic properties were predicted. In addition, the work focussed on application of ([BMIM]+[Tf2N]-) ionic liquid for the separations of (alkane/aromatic), (alkane/alk-1-ene), (cycloalkane/aromatic) and (water/alkan-1-ol) using gas- liquid chromatography (GLC) technique. The activity coefficients at infinite dilution, , for 31 organic solutes (alkanes, cycloalkanes, alkenes, alkynes, aromatics, alkanol and ketones) and water in ionic liquid were measured at temperatures of (323.15, 333.15, 343.15, 353.15 and 363.15) K. Stationary phase loadings of (42.83 and 68.66) % by mass were used to ensure repeatability of E , measurements. Partial molar excess enthalpies at infinite dilution, H1 , were also determined. The selectivities, S , and capacities, k , were determined for the above separations. The separating ij j ability of the investigated ionic liquid was compared with previously investigated ionic liquids and industrial solvents such as sulfolane, n-methyl-2-pyrrolidine (NMP) and n-formylmorpholine (NFM). The results obtained suggested that in general, the [BMIM]+[Tf2N]− had outperformed the conventional solvents such as sulfolane, NMP and NFM in terms of selectivity, while the [BMIM][Tf2N] had in general, performed better overall when the performance index was used for comparison.


2012 ◽  
Vol 55 ◽  
pp. 144-150 ◽  
Author(s):  
Marta Królikowska ◽  
Kamil Paduszyński ◽  
Tadeusz Hofman ◽  
Jerzy Antonowicz

Author(s):  
N. Golovata ◽  
N. Kotova ◽  
N. Usenko

In the present work, the Gibbs energies of mixing of liquid alloys of the Ge-Mn-Gd ternary system were determined, which was made on the basis of an analysis of published data on the thermodynamic properties of liquid alloys of boundary binary systems that form the ternary Ge-Mn-Gd, as well as on the basis of the model calculations in these binary systems. To determine the activities of the components, the Gibbs energies of mixing, and the enthalpies of mixing of liquid alloys of the Ge-Mn(Gd) systems, for which alloying process is accompanied by significant heat release, an ideal associated solution model was applied. For the melts of the Mn-Gd system, which are characterized by rather insignificant exothermic effects, a model of regular solutions was used. The surface of the Gibbs energy of mixing for the alloys of the Ge-Mn-Gd ternary system has been determined on the basis of the concentration dependences of the Gibbs energies of mixing obtained for constituent binary systems under the assumption of additivity of pair interactions using the Redlich-Kister-Muggianu method. The obtained topology of the Gibbs energy isolines projections is compared with the thermochemical properties of liquid alloys of this system that we have determined earlier. A comparative analysis of the topology of these surfaces in the Ge-Mn-Gd system led to the conclusion that the surfaces of ΔG and ΔmH monotonically decrease from the manganese-rich angle of the diagram towards the Ge-Gd side of the concentration triangle. The minimum value of the thermodynamic characteristics of mixing of the ternary liquid alloys corresponds to the composition, which coincides with the composition of the most stable intermetallic compound in the Ge-Gd system. From the course of isolines of free energies and integral enthalpies of mixing, one can also conclude about the influence of a short-range order, existed in the Ge-Mn system near the composition with a mole fraction of mangan greater than 0.7, on the properties of ternary alloys in the vicinity of this composition. Thus, the topology of isolines and the large exothermic values of the obtained thermodynamic properties allow us to make a reasonable conclusion that the strong interaction between unlike components inherent in the Ge-Gd system in the solid state is also maintained for liquid alloys of the Ge-Mn-Gd system.


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