scholarly journals Excess molar volume and isentropic compressibility for binary or ternary ionic liquid systems

2010 ◽  
Author(s):  
◽  
Indra Bahadur
Keyword(s):  
Ethyl Acetate ◽  
Molar Volume ◽  
Apparent Molar Volume ◽  
Infinite Dilution ◽  
Methyl Acetate ◽  
Isentropic Compressibility ◽  
Solvent Interactions ◽  
Binary Solutions ◽  
Pure Solvent ◽  
Experimental Density

The thermodynamic properties of mixtures involving ionic liquids (ILs) with alcohols or alkyl acetate or nitromethane at different temperatures were determined. The ILs used were methyl trioctylammonium bis(trifluoromethylsulfonyl)imide ([MOA]+[Tf2N]-) and 1-butyl-3- methylimidazolium methyl sulphate [BMIM]+[MeSO4]-. The ternary excess molar volumes (�������� E ) for the mixtures {methyl trioctylammonium bis (trifluoromethylsulfonyl)imide + methanol or ethanol + methyl acetate or ethyl acetate}and (1-butyl-3-methylimidazolium methylsulfate + methanol or ethanol or 1-propanol + nitromethane) were calculated from experimental density values, at T = (298.15, 303.15 and 313.15) K and T = 298.15, respectively. The Cibulka equation was used to correlate the ternary excess molar volume data using binary data from literature. The �������� E values for both IL ternary systems were negative at each temperature. The negative contribution of �������� E values are due to the packing effect and/or strong intermolecular interactions (ion-dipole) between the different molecules. The density and speed of sound of the binary solutions ([MOA]+[Tf2N]- + methyl acetate or ethyl acetate or methanol or ethanol), (methanol + methyl acetate or ethyl acetate) and (ethanol + methyl acetate or ethyl acetate) were also measured at T = ( 298.15, 303.15, 308.15 and 313.15) K and at atmospheric pressure. The apparent molar volume, Vφ , and the apparent molar isentropic compressibility, κφ , were evaluated from the experimental density and speed of sound data. A Redlich-Mayer type equation was fitted to the apparent molar volume and apparent molar isentropic compressibility data. The results are discussed in terms of solute-solute, solute- solvent and solvent-solvent interactions. The apparent molar volume and apparent molar isentropic compressibility at infinite dilution, ��φ �� and κφ ��, respectively of the binary solutions have been calculated at each temperature. The ��φ �� values for the binary v systems ([MOA]+[Tf2N]- + methyl acetate or ethyl acetate or methanol or ethanol) and (methanol + methyl acetate or ethyl acetate) and (ethanol + methyl acetate or ethyl acetate) are positive and increase with an increase in temperature. For the (methanol + methyl acetate or ethyl acetate) systems ��φ �� values indicate that the (ion-solvent) interactions are weaker. The κφ �� is both positive and negative. Positive κφ ��, for ([MOA] + [Tf2N]- + ethyl acetate or ethanol), (methanol + ethyl acetate) and (ethanol + methyl acetate or ethyl acetate) can be attributed to the predominance of solvent intrinsic compressibility effect over the effect of penetration of ions of IL or methanol or ethanol. The positive κφ �� values can be interpreted in terms of increase in the compressibility of the solution compared to the pure solvent methyl acetate or ethyl acetate or ethanol. The κφ �� values increase with an increase in temperature. Negative κφ ��, for ([MOA] + [Tf2N]- + methyl acetate or methanol), and (methanol + methyl acetate) can be attributed to the predominance of penetration effect of solvent molecules into the intra-ionic free space of IL or methanol molecules over the effect of their solvent intrinsic compressibility. Negative κφ �� indicate that the solvent surrounding the IL or methanol would present greater resistance to compression than the bulk solvent. The φ �� values decrease with an increase in the temperature. The infinite dilution apparent molar expansibility, ��φ �� , values for the binary systems (IL + methyl acetate or ethyl acetate or methanol or ethanol) and (methanol + methyl acetate or ethyl acetate) and (ethanol + methyl acetate or ethyl acetate) are positive and decrease with an increase in temperature due to the solution volume increasing less rapidly than the pure solvent. For (IL + methyl acetate or ethyl acetate or methanol or ethanol) systems ��φ �� indicates that the interaction between (IL + methyl acetate) is stronger than that of the (IL + ethanol) or (IL + methanol) or (IL + ethyl acetate) solution. For the (methanol + methyl acetate or ethyl acetate) systems ��φ �� values vi indicate that the interactions are stronger than (ethanol + methyl acetate or ethyl acetate) systems.

scholarly journals Using Volumetric Method the Study of Molecular Interactions of NSAID (DP) in Water and Water + 1M Urea at Different Temperatures

2021 ◽  
Vol 12 (3) ◽  
pp. 3956-3965
Keyword(s):  
Molar Volume ◽  
Molecular Interactions ◽  
Apparent Molar Volume ◽  
Solvent Interactions ◽  
Different Temperatures ◽  
Solute Interactions ◽  
Hydrotropic Agent ◽  
First Time ◽  
Molar Expansibility ◽  
Experimental Density

Understanding possible interactions of drugs and the factors that command such interactions could be helpful to control their disadvantageous effects upon human health. In this study, volumetric properties for the solution of diclofenac potassium (DP), a non-steroidal anti-inflammatory drug (NSAID), were investigated for the first time to look into its molecular interactions at four different temperatures varying from 298.15 K to 313.15 K at 5 K intervals in water as well as aqueous hydrotropic agent urea (1M) solutions. Experimental density data obtained using a pycnometer have been taken to estimate apparent molar properties, i.e., limiting apparent molar volume (〖V_ɸ〗^0), apparent molar volume (V_ɸ), limiting apparent molar expansibility (〖E_ɸ〗^0) and apparent molar expansibility (E_ɸ). The results obtained were discussed in terms of solute-solvent and solute-solute interactions in the studied systems. The obtained results from volumetric data were explored in terms of the existence of solute-solvent interactions in aqueous systems of drug solutions.

scholarly journals Density, speed of sound, refractive index and activity coefficients at infinite dilution for ionic liquids

2018 ◽  
Author(s):  
◽  
Ncomeka Mgxadeni
Keyword(s):  
Refractive Index ◽  
Ionic Liquid ◽  
Molar Volume ◽  
Activity Coefficients ◽  
Speed Of Sound ◽  
Excess Molar Volume ◽  
Infinite Dilution ◽  
Isentropic Compressibility ◽  
Hydrogen Sulfate ◽  
Experimental Density

In this study the experimental density, speed of sound, and refractive index for binary mixtures of an ionic liquid (IL): 1-butyl-3-methylimidazolium nitrate and activity coefficients at infinite dilution of organic solutes in the ionic liquid: 1-butyl-3-methylimidazolium hydrogen sulfate were determined. The density, speed of sound, and refractive index of 1-butyl-3-methylimidazolium nitrate in pyridine or acetonitrile or thiophene have been reported at T = 298.15 K, 303.15 K, 308.15 K, 313.15 K and 318.15 K using an Anton Paar DSA 5000M vibrating U-tube densimeter and a RXA 156 refractometer. The derived properties namely: excess molar volume, isentropic compressibility and change in refractive index were calculated from density, speed of sound and refractive index, respectively. The results are discussed in terms of molecular interactions (hydrogen bond, dipole-dipole, or ion-solvent or interactions). The negative deviation of excess molar volume and the positive deviation in change in refractive index clearly indicates the strong interaction of 1-butyl-3-methylimidazolium nitrate with pyridine or acetonitrile or thiophene in solution. The positive values of isentropic compressibility for the system indicates that the mixtures were more compressible than the ideal mixture. The Redlich Kister smoothing polynomial was used to fit the excess molar volume and deviation in isentropic compressibility data. The Lorentz-Lorenz equation was used to predict the experimental density, or refractive index data and to correlate the excess molar volume. Gas liquid chromatography was used to determine activity coefficients at infinite dilution for 28 polar and non-polar organic solute: alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, aldehydes, thiophene, pyridine and acetonitrile in an IL: 1-butyl-3- methylimidazolium hydrogen sulfate ([BMIM][HSO4]). The measured values of activity coefficients at infinite dilution for the solutes in [BMIM][HSO4] were carried out at T = (313.15, 323.15, 333.15) K. Partial molar excess enthalpies at infinite dilution of the organic solutes in the ionic liquid have been calculated from the temperature dependence of activity coefficients at infinite dilution. The selectivity and capacity values for separation problems namely: hexane/benzene, heptane/benzene, cyclohexane/benzene, ethanol/benzene, heptane/pyridine, heptane/thiophene and methanol/acetone at T = 323.15 K were calculated and compared to literature values for similar ionic liquids, sulfolane and N-methyl-2- pyrolidinone (NMP). The IL [BMIM][HSO4] gave both the highest selectivity and limiting capacity for the heptane/thiophene separation and would therefore be a suitable entrainer for this separation. New data from this study reveals that [BMIM][HSO4] may be proposed as a replacement solvent for the separation of sulphur or nitrogen compounds from alkanes.

scholarly journals ThermodynamicProperties of Nicotinicacid in Dilute HCl and inaqueous NaCl solutions at (293.15, 298.15, 303.15 and 308.15)K

2013 ◽  
Vol 10 (2) ◽  
pp. 432-441 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Nicotinic Acid ◽  
Molar Volume ◽  
Apparent Molar Volume ◽  
Infinite Dilution ◽  
Viscosity Data ◽  
Free Energies ◽  
Nacl Solution ◽  
Solute Interactions ◽  
Viscosity B Coefficient ◽  
Experimental Density

Apparent molar volume, V?, and viscosity B-coefficient of nicotinc acid in water and in aqueous NaCl solutions have been determined from density and viscosity measurements at (293.15, 298.15, 303.15 and 308.15) K. The experimental density data were evaluated by Masson equation, and the derived, apparent molar volume at infinite dilution, Vo?, and the slope Sv, were interpreted in term of solute-solvent and solute- solute interactions. Transfer apparent molar volumes at infinite dilution of nicotinic acid from water to NaCl solutions at various temperatures have been calculated.The viscosity data have been analyzed using Jones-Dole equation, and the derived parameters, Jones-Dolecoefficient, B,and Falkenhagen coefficient,A, have been also interpreted in terms of solute-solvent and solute-solute interactions respectively. The variation of B coefficient with temperature, (dB/dT), was also determined, the negative values indicate that nicotinic acid in aqueous NaCl solution is structure making. The results were interpreted in terms of complex vitamin-water-co-solute (NaCl) interactions. The free energy, enthalpy, andentropy of activation were calculated using the Nightingale, Benck, and Eyring equations. Free energies of activation of viscous flow ( *1) per mole, and, ( *2) per mole,of solvent and solute, respectively, were also calculated. The effects of soluteson the structure of water were interpreted in terms of viscositiesand the thermodynamic parameters.

Molecular Interactions Investigation of L-Histidine in Water and in Aqueous Citric Acid at Different Temperatures Using Volumetric and Acoustic Methods

2018 ◽  
Vol 232 (3) ◽  
pp. 393-408 ◽  
Author(s):  
Dinesh Kumar ◽  
Shashi Kant Sharma
Keyword(s):  
Citric Acid ◽  
Molar Volume ◽  
Atmospheric Pressure ◽  
Apparent Molar Volume ◽  
Adiabatic Compressibility ◽  
Acid Solutions ◽  
Solvent Interactions ◽  
Intermolecular Free Length ◽  
Acoustic Methods ◽  
Different Temperatures

AbstractDensities,ρand ultrasonic speeds, u of L-histidine (0.02–0.12 mol·kg−1) in water and 0.1 mol·kg−1aqueous citric acid solutions were measured over the temperature range (298.15–313.15) K with interval of 5 K at atmospheric pressure. From these experimental data apparent molar volume ΦV, limiting apparent molar volume ΦVOand the slopeSV, partial molar expansibilities ΦEO, Hepler’s constant, adiabatic compressibilityβ, transfer volume ΦV, trO, intermolecular free length (Lf), specific acoustic impedance (Z) and molar compressibility (W) were calculated. The results are interpreted in terms of solute–solute and solute–solvent interactions in these systems. It has also been observed that L-histidine act as structure maker in water and aqueous citric acid.

Characterizaton and Volumetric Studies of Magnetite (Fe3O4) Nanofluids at Different Temperatures

2015 ◽  
Vol 37 ◽  
pp. 28-35 ◽  
Author(s):  
Muhammad Asghar Jamal ◽  
Ammar Bin Yousaf ◽  
Muhammad Kaleem Khosa ◽  
Muhammad Usman ◽  
Majid Khan
Keyword(s):  
Particle Size ◽  
Molar Volume ◽  
Atmospheric Pressure ◽  
Apparent Molar Volume ◽  
Isentropic Compressibility ◽  
Size Difference ◽  
Volumetric Properties ◽  
Practical Applications ◽  
Different Temperatures ◽  
Uv Visible

Magnetite nanofluid has been prepared in citric acid based medium. Their stability and polydispersity level have been characterized by UV-visible spectrophotometry.The volumetric properties such as apparent molar volume, partial molar volume and isentropic compressibility of nanofluid have been measured at temperature range from 298.15K to 313.15K at atmospheric pressure. The obtained results were interpreted in terms of particle-particle and particle-fluid interactions, and compared with commercially available magnetite nanofluid in terms of particle size difference. It was observed that the influence of particle size on measured volumetric parameters is significant for any practical applications of fluid flow. The differences in measured quantities were determined qualitatively by considering the state of aggregation / particle size distribution of the nanofluids.

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