Mixtures Of Diethyl Carbonate Research Articles

Characterisation of plasticised PVDF–HFP polymer electrolytes

This study focuses on the preparation and characterisation of sodium ion conducting polymer electrolytes. Poly(vinylidenefluoride-co-hexafluoropropylene) has been used as the host matrix and hydrated sodium sulphide (Na2S.9H2O) salt as the source of charge carriers in the polymer electrolyte system. To the highest conducting polymer–salt electrolyte, different concentrations of equal weight of propylene carbonate and diethyl carbonate mixture have been added, and the electrolytes have been characterised by X-ray diffraction, Fourier transform infrared spectrometry, scanning electron microscopy and electrochemical impedance spectroscopy. The room temperature ionic conductivity of 1·34×10−4 S cm−1 for the unplasticised electrolyte with a composition of 65 wt-% poly(vinylidenefluoride-co-hexafluoropropylene)–35 wt-%Na2S increased to 3·49×10−4 S cm−1 when 30 wt-% propylene carbonate/diethyl carbonate (w/w = 1) plasticisers were added.

Densities and Viscosities of Four Binary Diethyl Carbonate + 1-Alcohol Systems from (288.15 to 313.15) K

Densities and viscosities of the binary mixtures of diethyl carbonate (DEC) with ethanol, 1-propanol, 1-pentanol, and 1-octanol were measured over the entire mole fraction at (288.15, 293.15, 303.15, and 313.15) K and normal atmospheric pressure. Moreover, the excess molar enthalpies for the present binary mixtures were determined at 303.15 K. Other mixing properties such as the excess molar volumes have been also obtained for each of the systems and temperatures. The composition–viscosity data were correlated with several specific equations to evaluate their suitability for these systems.

Characterization of poly(vinylidenefluoride-co-hexafluoroprolylene) membranes containing nanoscopic AlO(OH)n filler with Li/LiFePO4 cell

This paper describes the nanoscopic AlO(OH)n filled in porous poly(vinylidenefluoride-co-hexafluoroprolylene) membranes by phase inversion technique. The membranes were gelled with 0.5M LiPF6 in ethylene carbonate and diethyl carbonate mixture for characterization studies. The inclusion of AlO(OH)n nanoparticles substantially enhances the ionic conductivity and mechanical and thermal stabilities, which were observed through ac impedance, tensile strength, and differential scanning calorimetry. For example, the ionic conductivity has been increased from 2.1×10−3 to 3.9×10−3 S cm−1 after the inclusion of nanoparticles. Similarly, the elongation break value is improved from 277% to 464% for the incorporation of nanoparticles. A morphological feature of the membrane was analyzed by scanning electron microscopy. Further, physicochemical properties, such as liquid uptake, porosity measurements, activation energy, and percentage of crystallinity, have also been presented. Finally, Li/polymer membrane/LiFePO4 cell was fabricated, and cycling performance of the cell was evaluated at C/10 rate. The cell delivers the initial discharge capacity 149 mAh/g at ambient temperature conditions.

Lithium fluoroalkylphosphate based novel composite polymer electrolytes (NCPE) incorporated with nanosized SiO 2 filler

This paper describes the preparation and characterization of polyvinylidene fluoride–hexafluoropropylene (PVdF–HFP) based nanocomposite polymer electrolyte (NCPE). For the first of its kind lithium fluoroalkylphosphate (LiPF 3(CF 3CF 2) 3) was incorporated as electrolyte salt in the polymer skeleton. Ethylene carbonate and diethyl carbonate mixture (1:1, wt/wt) was used as a plasticizing agent and SiO 2 nanoparticle as filler. The NCPE membranes were characterized by a.c. impedance, Scanning electron microscope, Differential scanning calorimetry, Fourier transform infrared and fluorescence studies. An electrolyte with 2.5 wt% SiO 2 exhibited a conductivity of 1.16 mS cm −1 at ambient temperature. It was found that filler contents above 2.5 wt% rendered the membranes less conducting. Activation energy and percentage of crystallinity has also been calculated.

Investigations on Na+ ion conducting polyvinylidenefluoride-co-hexafluoropropylene/poly ethylmethacrylate blend polymer electrolytes

Sodium ion conducting composite polymer electrolytes (CPE) have been prepared by solution casting technique in the skeleton of polyvinylidenefluoride-co-hexafluoropropylene/poly ethylmethacrylate blend. The binary mixture of diethyl carbonate and ethylene carbonate were used as plasticizer, and nanosized Sb2O3 as filler. The sodium trifluoromethanesulfonate (NaCF3SO3) was used as an ionic conducting source. The a.c. impedance study shows that 10wt% Sb2O3 containing CPE exhibits the maximum conductivity 0.569mScm−1 at ambient temperature. Molecular interactions of the constituents were analyzed by Fourier transform infra red spectroscopy. X-ray diffractogram reveals the amorphous nature of the CPE. A surface morphological feature was studied through scanning electron microscope. The activation energy and coherence length calculated were in support of the ionic transport.

Thermodynamic studies of ternary mixtures of diethylcarbonate (1) + dimethylcarbonate (2) + N, N-dimethylacetamide (3) at 298.15 K

The densities ρ, and viscosities η, of pure diethylcarbonate, dimethylcarbonate, and N, N-dimethylacetamide and those of their binary and ternary mixtures have been measured at 298.15 K and atmospheric pressure over the entire range of compositions. Excess molar volumes V 123 E, viscosity deviations Δ η 123, and excess Gibbs energy of activation G 123 ⁎ E, were obtained from the experimental results. The values for the binary and ternary systems were fitted to Redlich−Kister's and Cibulka's type function in terms of mole fractions, respectively. McAllister's three body interaction model is used for correlating the kinematic viscosity of binary mixtures with mole fraction. The experimental data of the constitute binaries and ternary are analyzed to discuss the nature and strength of intermolecular interactions in these mixtures.

Densities, Viscosities, Speeds of Sound, and Refractive Indices for Binary Mixtures of Diethylcarbonate, Acetophenone, and 1-Hexanol at (293.15, 303.15, 313.15, and 323.15) K for the Liquid Region and at Ambient Pressure

Densities, viscosities, speeds of sound, and refractive indices of the binary systems formed by (diethylcarbonate + acetophenone), (diethylcarbonate + 1-hexanol), and (acetophenone + 1-hexanol) were measured at (293.15, 303.15, 313.15, and 323.15) K for the liquid region and at ambient pressure for the whole composition range. Deviations in viscosity (Δη) from the mole fraction average, deviations in isentropic compressibility (Δκs), and deviations in the refractive index (ΔnD) from the volume fraction average for the mixtures were derived from the experimental data. The binary data of Δη, Δκs, and ΔnD were correlated as a function of the mole fraction by using the Redlich−Kister-type function to determine the fitting parameters and the standard deviations. McAllister's four-body interaction model is used for correlating the kinematic viscosity of binary mixtures. The speeds of sound have been compared with values calculated from the free length theory (FLT) due to Jacobson and the collision factor theory...

Densities and derived thermodynamic properties of binary mixtures of diethylcarbonate, acetophenone, and 1-hexanol at T = (293.15 to 323.15) K for the liquid region and at ambient pressure

Densities of the binary mixtures of (diethylcarbonate + acetophenone), (diethylcarbonate + 1-hexanol), and (acetophenone + 1-hexanol) were measured at T = (293.15, 303.15, 313.15, and 323.15) K for the liquid region and at ambient pressure over the whole composition range using a vibrating U-tube densimeter. The excess molar volumes V m E , partial molar volumes V ¯ m, i , limiting partial molar volumes V ¯ m, i ∞ , thermal expansion coefficients α, and their excess values α E, and isothermal excess molar enthalpy–pressure derivative ( ∂ H m E / ∂ P ) T , x , were calculated from experimental densities. The binary data of V m E and α E were correlated as a function of the mole fraction by using the Redlich–Kister type function to determine the fitting parameters and the standard deviations. The experimental data of the constituent binaries are analysed to discuss the nature and strength of intermolecular interactions in these mixtures.

Density and Viscosity of Binary Mixtures of Diethyl Carbonate with Alcohols at (293.15 to 363.15) K and Predictive Results by UNIFAC-VISCO Group Contribution Method

Densities and viscosities of the binary mixtures of diethyl carbonate (DEC) with 1-propanol, 1-butanol, and 1-pentanol have been determined at (293.15 to 363.15) K and at atmospheric pressure. Excess molar volumes and viscosity deviations for the binary mixtures were fitted to the Redlich−Kister equation. Dependences of excess molar volumes and viscosity deviations with carbon chain length were discussed. The UNIFAC-VISCO method, based on contribution groups, has been used to calculate the dynamic viscosities of the binary mixtures. The percentage deviations between experimental and predicted values are given.

Nanostructured material based on Tin and Titanium Oxides: A potentiodynamic study

Electrochemical behavior of the diamond-based composites: a nanodiamond—pyrocarbon composite and Carbal, as well as vacuum-high-temperature-annealed polycrystalline diamond is studied by the cathodic lithium incorporation from LiPF 6 solution in a (1 : 4) propylene carbonate—diethyl carbonate mixture. The amount of incorporated lithium steadily increases with the nondiamond (graphite-like) carbon content in the composite. The intercalation capacity of Carbal equals ~33 mA-h per g of the graphite-like carbon. It is concluded that the graphite-like carbon distributed in the nano-(or micro-)diamond carcass is the electrochemically active phase in the composites.

Excess Molar Volumes and Partial Molar Volumes of Binary Mixtures Containing Diethylcarbonate with Benzene and Substituted Benzenes at 293.15 K

Densities of the binary mixtures of diethylcarbonate with benzene and substituted benzenes, namely toluene, bromobenzene, chlorobenzene and nitrobenzene have been measured as a function of the composition, at 293.15 K and atmospheric pressure using a bicapillary pycnometer with an accuracy of 4 parts in 104.The calculated excess molar volumes, V E were correlated with Redlich-Kister equation. The excess molar volumes are negative over the entire range of composition for the systems diethylcarbonate with benzene, toluene, bromobenzene and nitrobenzene. An inversion of the sign of V E is observed over some concentration for mixtures of diethylcarbonate with chlorobenzene. Partial molar volumes, Vi are also evaluated and their values have been extrapolated to zero concentration to obtain the limiting value at infinite dilution, Vo i . The numerical values of the excess molar volumes for binary mixtures decrease in the order: chlorobenzene > benzene > bromobenzene ≈ toluene > nitrobenzene. The results are explained in terms of dissociation of the self-associated solute molecules and the formation of aggregates between unlike molecules.

Excess molar enthalpies of diethyl carbonate with o-xylene, m-xylene, p-xylene, ethylbenzene, or ethyl benzoate at 298.15 K

Excess molar enthalpies ( H E) of binary mixtures of diethyl carbonate with o-xylene, m-xylene, p-xylene, ethylbenzene, or ethyl benzoate were measured by a flow-type isothermal microcalorimeter at 298.15 K under atmospheric pressure. The experimental results show that all the excess enthalpies are positive and vary symmetrically with the mole fraction of diethyl carbonate. It was also found that the maximum values of H E are in a range of 59.7–123.4 J mol −1 for these five investigated systems. The magnitudes of the maximum H E follow the order of: m-xylene>ethylbenzene> o-xylene> p-xylene>ethyl benzoate. In addition to the Redlich–Kister equation, the Peng–Robinson and the Cubic Chain-of-Rotators equations of state were also used to correlate the experimental H E data. These two equations of state represent the H E data reasonably well, except for the system containing ethyl benzoate.

Density, Refractive Index, and Speed of Sound of Binary Mixtures (Diethyl Carbonate + Alcohols) at Several Temperatures

Density, ρ; refractive index on mixing, nD; and speed of sound, u; at 293.15 K, 298.15 K, 303.15 K, and 313.15 K and atmospheric pressure have been measured for binary mixtures of diethyl carbonate (DEC) + methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, or 1-pentanol. Excess molar volumes, VE; changes of refractive index on mixing, ΔnD; and deviations in isentropic compressibility, ΔκS; for the above systems have been calculated. The Redlich−Kister equation has been used to estimate the binary fitting parameters, and root-mean-square deviations from the regression lines are shown. The VE values were fitted as a function of the mole fraction and temperature to a polynomial equation.

Thermophysical Properties of the Binary Mixtures Diethyl Carbonate + (n-Dodecane or n-Tetradecane) at Several Temperatures

The density and the speed of sound at (288.15, 293.15, 298.15, and 308.15) K and the isobaric molar heat capacity at (288.15, 298.15, and 308.15) K of binary mixtures of diethyl carbonate with n-dodecane or n-tetradecane were measured at atmospheric pressure, over the entire composition range. These results are used to calculate molar volumes, isentropic and isothermal compressibilities, isobaric thermal expansivities, and isobaric and isochoric molar heat capacities as well as the corresponding excess quantities. Positive values and a parabolic composition dependence were found for all excess quantities except for the excess molar heat capacities, which take negative values and are W-shaped. Excess molar volumes increase with both alkyl chain length of the n-alkane and temperature. Excess isobaric molar heat capacities decrease as the size of the n-alkane increases and exhibit different temperature dependences with mole fraction. All other properties, with the exception of the excess isochoric molar heat...

Isothermal Vapor−Liquid Equilibria of Dimethyl Carbonate + Diethyl Carbonate in the Range (313.15 to 353.15) K

Isothermal vapor−liquid equilibria (VLE) have been determined for the dimethyl carbonate + diethyl carbonate mixture at five temperatures in the range (313.15 to 353.15) K in an equilibrium still with circulation of both the vapor and liquid phases. The data have been correlated by means of the Wilson equation. The system shows small positive deviations from ideality with liquid-phase activity coefficients not exceeding 1.26.

Excess molar enthalpies of binary mixtures containing dimethyl carbonate or diethyl carbonate and one of six methyl n-alkyl ketones Application of an extended cell model

Excess molar enthalpies H E m of binary mixtures containing dimethyl carbonate or diethyl carbonate and six methyl n-alkyl ketones have been determined at 298.15 K and atmospheric pressure using a flow microcalorimeter. The systematic behaviour of H E m, increasing with the increase in the number of the carbon atoms in the ketone, is confirmed for all mixtures with the exception of mixtures of diethyl carbonate and 2-propanone. The experimental data have been correlated by means of the Redlich-Kister equation and results are interpreted in terms of molecular interactions, and are examined by an extended cell model.

Excess molar volumes of diethyl carbonate with hydrocarbons or tetrachloromethane at 25�C

The excess molar volumes V m E at atmospheric pressure and at 25°C for binary mixtures of diethyl carbonate with n-heptane, n-decane, n-tetradecane, 2,2,4-trimethylpentane, cyclohexane, benzene, toluene, or tetrachloromethane have been obtained over the whole mole-fraction range from densities measured with a vibrating-tube densimeter. The V m E are positive for all the systems investigated, except for the mixture with toluene which is negative. The results for V m E together with data previously published on excess molar enthalpies H m E and excess molar Gibbs energies G m E , suggest interactions between carbonate and hydrocarbons which are stronger with aromatic than with aliphatic hydrocarbons.

Excess Molar Enthalpy of Binary Mixtures of Diethyl Carbonate + Nine Chloroalkanes at 298.15 K and Atmospheric Pressure

Excess molar enthalpies, H m E , of binary mixtures of diethyl carbonate + nine chloroalkanes have been determined at 298.15 K and atmospheric pressure by using a flow isothermal microcalorimeter. The H m E values range from a minimum value of -2600 J mol -1 up to 340 J mol -1 . In the case of diethyl carbonate + dichloroalkanes, H m E increases with the increase of the chain length of the dichloro compound. Experimental data have been correlated by means of the Redlich-Kister equation, and adjustable parameters have been evaluated by the least-squares method.