Engenharia Química
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/25
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3 resultados
Resultados da Pesquisa
- Thermodynamic properties of binary mixtures of n-butylammonium-based ionic liquids with ethanol at T = (293.15–313.15) K(2019) Bittencourt S.S.; Hoga H.E.; Torres R.B.; d'Angelo J.V.H.© 2018, Akadémiai Kiadó, Budapest, Hungary. In this study, density, speed of sound and viscosity of binary mixtures of ionic liquids + ethanol have been measured as a function of composition at T = (293.15–313.15) K and atmospheric pressure. The ionic liquids studied were: {n-butylammonium acetate (N4Ace), n-butylammonium propanoate (N4Pro), n-butylammonium hexanoate (N4Hex), and n-butylammonium decanoate (N4Dec)}. Excess molar volume, VmE, deviation in isentropic compressibility, Δ κ S , deviation in viscosity, Δ η, and excess Gibbs energy of activation of viscous flow, Δ G ∗ E , were obtained from experimental results and correlated with the Redlich–Kister polynomial equation. Ionic liquids were synthesized and characterized using 1 H-NMR, 13 C-NMR and FTIR spectroscopy techniques. For all systems studied, the values of VmE, Δ κ S and Δ η were negative over the entire composition range, whereas Δ G ∗ E values were positive over the entire composition range. The results obtained were discussed in terms of structural effects and intermolecular interactions between like and unlike molecules.
- Thermodynamics properties of binary mixtures of aqueous solutions of glycols at several temperatures and atmospheric pressure(2018) Hoga H.E.; Torres R.B.; Volpe P.L.O.© 2018 Elsevier LtdDensities (ρ), speeds of sound (u) and viscosities (η) for binary mixtures of {water + ethanol, or + ethylene glycol (EG), or + diethylene glycol (DEG), or + triethylene glycol (TEG), or + polyethylene glycol (PEG) 200, or + polyethylene glycol (PEG) 300, or + polyethylene glycol (PEG) 400, or + polyethylene glycol (PEG) 600, or + glycerol} have been determined as a function of composition at T = (293.15, 298.15, 303.15 and 308.15 K) and atmospheric pressure. From these results, excess molar volume (VmE), deviation in isentropic compressibility (ΔκS), deviation in viscosity (Δη), and excess Gibbs energy of activation for viscous flow (ΔG∗E) were calculated and fitted by the Myers-Scott equation, as a function of mole fraction. Values of VmE and ΔκS were negative over the entire composition range for all mixtures studied. The values of Δη were negative for the systems containing ethylene glycol and glycerol and positive for the systems containing ethanol, PEG 400 and PEG 600. For other systems, the deviation of viscosity presented an S-shape, with negative values at high water concentration. For all mixtures studied, the values of ΔG∗E were positive over the entire composition range. The results obtained were discussed in terms of structural effects and intermolecular interactions between like and unlike molecules.
- Thermodynamic and spectroscopic properties of binary mixtures of n-butylammonium butanoate ionic liquid with alcohols at T = (293.15–313.15) K(2017) Bittencourt S.S.; Hoga H.E.; Torres R.B.; d'Angelo J.V.H.© 2016 Elsevier LtdIn this work, density and speed of sound of binary mixtures of {n-butylammonium butanoate ionic liquid (N4Bu) + alcohols (methanol, ethanol, 1-propanol, 1-butanol and 1-pentanol)} have been measured as a function of composition at T = (293.15–313.15) K and atmospheric pressure. The results were used to calculate the excess molar volume, VmE, and deviation in isentropic compressibility, ΔκS, and correlated to the Redlich-Kister polynomial equation. N4Bu was synthesized by the method of acid-base neutralization reaction using n-butylamine and butanoic acid, and characterized using 1H NMR, 13C NMR and FTIR spectroscopy techniques. For all systems studied, the values of excess molar volumes and deviations in isentropic compressibility were negative over the entire composition range. The results obtained were discussed in terms of structural effects and intermolecular interactions between like and unlike molecules.