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J H Vera - One of the best experts on this subject based on the ideXlab platform.
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activity coefficients of the peptide and the electrolyte in ternary systems water Glycylglycine nacl nabr kcl and kbr at 298 2 k
Biophysical Chemistry, 2001Co-Authors: Youngmi Chung, J H VeraAbstract:The activity coefficients of Glycylglycine in four aqueous electrolyte solutions (+NaCl, +NaBr, +KCl and +KBr) were obtained at 298.2 K. The mean ionic activity coefficient of the electrolyte in aqueous solutions containing the peptide was determined from measurements of the potential differences of a cation and an anion ion-selective-electrode, each vs. a double junction reference electrode. The results show that the nature of the anion has a major effect on the activity coefficients of Glycylglycine. Comparison of activity coefficient data for Glycylglycine with literature data for glycine, both in aqueous NaCl solutions, indicates that the effect of the electrolyte is larger for the peptide than for the amino acid. For the peptide, in all cases, the effect of the electrolyte is more important at low molalities of the electrolyte. The Wilson equation was used to correlate the activity coefficient data obtained. The correlation results were satisfactory for the region of concentrated electrolyte.
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Activity coefficients of the peptide and the electrolyte in ternary systems water+Glycylglycine+NaCl, +NaBr, +KCl and +KBr at 298.2 K.
Biophysical chemistry, 2001Co-Authors: Y M Chung, J H VeraAbstract:The activity coefficients of Glycylglycine in four aqueous electrolyte solutions (+NaCl, +NaBr, +KCl and +KBr) were obtained at 298.2 K. The mean ionic activity coefficient of the electrolyte in aqueous solutions containing the peptide was determined from measurements of the potential differences of a cation and an anion ion-selective-electrode, each vs. a double junction reference electrode. The results show that the nature of the anion has a major effect on the activity coefficients of Glycylglycine. Comparison of activity coefficient data for Glycylglycine with literature data for glycine, both in aqueous NaCl solutions, indicates that the effect of the electrolyte is larger for the peptide than for the amino acid. For the peptide, in all cases, the effect of the electrolyte is more important at low molalities of the electrolyte. The Wilson equation was used to correlate the activity coefficient data obtained. The correlation results were satisfactory for the region of concentrated electrolyte.
Valentin G. Badelin - One of the best experts on this subject based on the ideXlab platform.
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Thermochemical study of Glycylglycine interaction with polyhydric alcohols in aqueous solution
Russian Journal of General Chemistry, 2015Co-Authors: I. N. Mezhevoi, Valentin G. BadelinAbstract:Integral enthalpies of Glycylglycine dissolution (Δsol H m ) in aqueous solutions of glycerol, ethylene glycol, and propylene glycol have been determined at the organic co-solvent concentration up to 32 mol %. The standard dissolution enthalpy (Δsol H 0) and standard enthalpy of transfer of the peptide from water into the binary solvent (Δtr H 0) have been calculated. The influence of various types of interactions and the structural features of the interacting molecules on the enthalpy of Glycylglycine dissolution has been analyzed.
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Enthalpies of solution of Glycylglycine in water–organic solvent media at 298.15 K
Thermochimica Acta, 2010Co-Authors: Valeriy I. Smirnov, Valentin G. BadelinAbstract:Abstract The enthalpies of solution of Glycylglycine in aqueous solution of 1,4-dioxane, acetone, formamide, N-methylformamide and N,N-dimethylformamide, with the co-solvent content up to 0.4 mole fractions, have been measured calorimetrically at T = 298.15 K. The results obtained were used to calculate the standard enthalpies of solution (ΔsolH°) and transfer (ΔtrH°) of the Glycylglycine from water into the mixtures as well as the enthalpy coefficients of pair-wise interaction hxy of the solute with the organic co-solvents in aqueous media. The hxy values were correlated with the properties of organic solvents using the Kamlet–Taft equation. The effect of the structure properties of the mixed solvent on the specified enthalpy characteristics of Glycylglycine is discussed.
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enthalpies of solution of Glycylglycine in water organic solvent media at 298 15 k
Thermochimica Acta, 2010Co-Authors: Valeriy I. Smirnov, Valentin G. BadelinAbstract:Abstract The enthalpies of solution of Glycylglycine in aqueous solution of 1,4-dioxane, acetone, formamide, N-methylformamide and N,N-dimethylformamide, with the co-solvent content up to 0.4 mole fractions, have been measured calorimetrically at T = 298.15 K. The results obtained were used to calculate the standard enthalpies of solution (ΔsolH°) and transfer (ΔtrH°) of the Glycylglycine from water into the mixtures as well as the enthalpy coefficients of pair-wise interaction hxy of the solute with the organic co-solvents in aqueous media. The hxy values were correlated with the properties of organic solvents using the Kamlet–Taft equation. The effect of the structure properties of the mixed solvent on the specified enthalpy characteristics of Glycylglycine is discussed.
Youngmi Chung - One of the best experts on this subject based on the ideXlab platform.
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activity coefficients of the peptide and the electrolyte in ternary systems water Glycylglycine nacl nabr kcl and kbr at 298 2 k
Biophysical Chemistry, 2001Co-Authors: Youngmi Chung, J H VeraAbstract:The activity coefficients of Glycylglycine in four aqueous electrolyte solutions (+NaCl, +NaBr, +KCl and +KBr) were obtained at 298.2 K. The mean ionic activity coefficient of the electrolyte in aqueous solutions containing the peptide was determined from measurements of the potential differences of a cation and an anion ion-selective-electrode, each vs. a double junction reference electrode. The results show that the nature of the anion has a major effect on the activity coefficients of Glycylglycine. Comparison of activity coefficient data for Glycylglycine with literature data for glycine, both in aqueous NaCl solutions, indicates that the effect of the electrolyte is larger for the peptide than for the amino acid. For the peptide, in all cases, the effect of the electrolyte is more important at low molalities of the electrolyte. The Wilson equation was used to correlate the activity coefficient data obtained. The correlation results were satisfactory for the region of concentrated electrolyte.
Lanying Zhu - One of the best experts on this subject based on the ideXlab platform.
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enthalpy of dilution and volumetric properties of n Glycylglycine in aqueous xylitol solutions at t 298 15 k
The Journal of Chemical Thermodynamics, 2011Co-Authors: Min Liu, Lili Wang, Dezhi Sun, Lina Dong, Lanying ZhuAbstract:Abstract The enthalpy of dilution of N-Glycylglycine (ΔdilHm) in aqueous xylitol solutions has been determined by means of flow-mix isothermal microcalorimetry at the temperature of 298.15 K. The homogeneous enthalpic interaction coefficients (h2, h3, and h4) which characterize the interactions of examined N-Glycylglycine in aqueous xylitol solutions have been calculated according to the excess enthalpy concept based on the values of dilution enthalpy. It has been found that the enthalpic pair interaction coefficients (h2) in the systems investigated are negative and become less negative as the molality of xylitol increases. Values of the density (ρ) of the ternary homogeneous systems were also measured with a quartz vibrating-tube densimeter at the temperature of 298.15 K. The values of the apparent molar volume (Vϕ) of the ternary systems were calculated from the data of density, which have been used to deduce limiting partial molar volumes of N-Glycylglycine ( V ϕ o ) and limiting partial molar volumes of transfer ( Δ trs V ϕ o ) from water to aqueous xylitol solutions at different concentrations. The results have been discussed based on solute–solute interactions and solvation effects.
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Enthalpy of dilution and volumetric properties of N-Glycylglycine in aqueous xylitol solutions at T = 298.15 K
The Journal of Chemical Thermodynamics, 2011Co-Authors: Min Liu, Lili Wang, Dezhi Sun, Lina Dong, Lanying ZhuAbstract:Abstract The enthalpy of dilution of N-Glycylglycine (ΔdilHm) in aqueous xylitol solutions has been determined by means of flow-mix isothermal microcalorimetry at the temperature of 298.15 K. The homogeneous enthalpic interaction coefficients (h2, h3, and h4) which characterize the interactions of examined N-Glycylglycine in aqueous xylitol solutions have been calculated according to the excess enthalpy concept based on the values of dilution enthalpy. It has been found that the enthalpic pair interaction coefficients (h2) in the systems investigated are negative and become less negative as the molality of xylitol increases. Values of the density (ρ) of the ternary homogeneous systems were also measured with a quartz vibrating-tube densimeter at the temperature of 298.15 K. The values of the apparent molar volume (Vϕ) of the ternary systems were calculated from the data of density, which have been used to deduce limiting partial molar volumes of N-Glycylglycine ( V ϕ o ) and limiting partial molar volumes of transfer ( Δ trs V ϕ o ) from water to aqueous xylitol solutions at different concentrations. The results have been discussed based on solute–solute interactions and solvation effects.
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Enthalpies of Dilution of N-Glycylglycine in Aqueous Sodium Chloride and Potassium Chloride Solutions at 298.15 K
Journal of Chemical & Engineering Data, 2009Co-Authors: Lili Wang, Min Liu, Lanying Zhu, Dezhi SunAbstract:The enthalpies of dilution of N-Glycylglycine in aqueous sodium chloride and potassium chloride solutions have been determined by using flow microcalorimetry at 298.15 K. The homogeneous enthalpic interaction coefficients (h2, h3, h4) in the range of sodium chloride and potassium chloride molality, (0 to 0.6) mol·kg−1, have been calculated according to the McMillan−Mayer theory. It shows that the enthalpic pairwise interaction coefficients h2 of N-Glycylglycine in both electrolyte solutions are negative, and the value of h2 in aqueous sodium chloride solutions is less than that in aqueous potassium chloride solutions of the same molality. The values of h2 for N-Glycylglycine in aqueous solutions of sodium chloride pass through a minimum at about 0.10 mol·kg−1, while the corresponding values of h2 in aqueous potassium chloride solutions become less negative with an increase in the molality of potassium chloride. The results are discussed in terms of the solute−solute and solute−solvent interactions.
Valeriy I. Smirnov - One of the best experts on this subject based on the ideXlab platform.
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Enthalpies of solution of Glycylglycine in water–organic solvent media at 298.15 K
Thermochimica Acta, 2010Co-Authors: Valeriy I. Smirnov, Valentin G. BadelinAbstract:Abstract The enthalpies of solution of Glycylglycine in aqueous solution of 1,4-dioxane, acetone, formamide, N-methylformamide and N,N-dimethylformamide, with the co-solvent content up to 0.4 mole fractions, have been measured calorimetrically at T = 298.15 K. The results obtained were used to calculate the standard enthalpies of solution (ΔsolH°) and transfer (ΔtrH°) of the Glycylglycine from water into the mixtures as well as the enthalpy coefficients of pair-wise interaction hxy of the solute with the organic co-solvents in aqueous media. The hxy values were correlated with the properties of organic solvents using the Kamlet–Taft equation. The effect of the structure properties of the mixed solvent on the specified enthalpy characteristics of Glycylglycine is discussed.
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enthalpies of solution of Glycylglycine in water organic solvent media at 298 15 k
Thermochimica Acta, 2010Co-Authors: Valeriy I. Smirnov, Valentin G. BadelinAbstract:Abstract The enthalpies of solution of Glycylglycine in aqueous solution of 1,4-dioxane, acetone, formamide, N-methylformamide and N,N-dimethylformamide, with the co-solvent content up to 0.4 mole fractions, have been measured calorimetrically at T = 298.15 K. The results obtained were used to calculate the standard enthalpies of solution (ΔsolH°) and transfer (ΔtrH°) of the Glycylglycine from water into the mixtures as well as the enthalpy coefficients of pair-wise interaction hxy of the solute with the organic co-solvents in aqueous media. The hxy values were correlated with the properties of organic solvents using the Kamlet–Taft equation. The effect of the structure properties of the mixed solvent on the specified enthalpy characteristics of Glycylglycine is discussed.