[en] Highlights: • The study reports density, ultrasonic speed and viscosity data of l-threonine in aqueous-sucrose solutions. • The study elucidates interactions of l-threonine with sucrose in aqueous media. • Provides data to estimate physicochemical properties of proteins in these media. • Correlates physicochemical properties of l-threonine with its behaviour in aqueous-sucrose solutions. -- Abstract: Densities, ρ of solutions of l-threonine in aqueous-sucrose solvents 5%, 10%, 15%, and 20% of sucrose, w/w in water at T = (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K; and ultrasonic speeds, u and viscosities, η of these solutions at 298.15, 303.15, 308.15, 313.15, and 318.15 K were measured at atmospheric pressure. From these experimental results, the apparent molar volume, V_ϕ, limiting apparent molar volume, V_ϕ^∘ and the slope, S_v, apparent molar compressibility, K_s,ϕ, limiting apparent molar compressibility, K_s,ϕ^∘ and the slope, S_k, transfer volume, V_ϕ,tr^∘, transfer compressibility, K_s,ϕ,tr^∘, limiting apparent molar expansivity, E_ϕ^∘, Hepler’s constant, (∂²V_ϕ^∘/dT²), Falkenhagen coefficient, A, Jones–Dole coefficient, B and hydration number, n_H have been calculated. The results have been interpreted in terms of solute–solvent and solute–solute interactions in these systems. The Gibbs energies of activation of viscous flow per mole of solvent, Δμ₁^{∘numbersign} and per mole of solute, Δμ₂^{∘numbersign} were also calculated and discussed in terms of transition state theory. It has been observed that there exist strong solute–solvent interactions in these systems and these interactions increase with increase in sucrose concentration in solution

[en] Highlights: • Provides density and viscosity data for l-arginine in aqueous-arabinose/xylose solutions. • Elucidates interactions of l-arginine in aqueous-arabinose/xylose solutions. • Correlates physicochemical properties of l-arginine with its behaviour in solution. -- Abstract: Densities, ρ of l-arginine in water and in aqueous–d-xylose/l-arabinose (2.5% and 5% of d-xylose/l-arabinose, w/w in water) mixed solvents were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K, and viscosities, η of these solutions at temperatures (298.15, 303.15, 308.15, 313.15 and 318.15) K were measured at atmospheric pressure. From the density values, the apparent molar volume, V_ϕ, limiting apparent molar volume, V_ϕ^°, slope, S_v and transfer volume, V_ϕ,tr^° and hydration number, n_H were calculated. The viscosity values have been analysed on the basis of the Jones–Dole equation; and Falkenhagen Coefficient, A and Jones–Dole coefficient, B were calculated. The Gibbs energies of activation of viscous flow per mole of solvent, Δμ₁^°numbersign and per mole of solute, Δμ₂^°numbersign were also calculated. The results indicate that there exist strong solute–solvent interactions in these systems, which increase with increase in carbohydrate concentration in both the solvents. It is observed that l-arginine act as a structure-maker in both these solvent systems

[en] Highlights: • The study reports density, ultrasonic speed and viscosity data of l-phenylalanine in aqueous-carbohydrate solutions. • The study elucidates interactions of l-phenylalanine with carbohydrates in aqueous media. • Correlates physicochemical properties of l-phenylalanine with its behavior in aqueous-carbohydrate solutions. • The structure-making/breaking ability of l-phenylalanine in these aqueous-carbohydrate solutions is reported. -- Abstract: The values of density, ρ and ultrasonic speed, u of solutions of l-phenylalanine in aqueous-carbohydrate solvents (2.5 and 5% of arabinose/glucose/sucrose, w/w in water) at T = (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K; and viscosities, η of these solutions at (298.15, 303.15, 308.15, 313.15, and 318.15) K and at atmospheric pressure were measured. From these experimental results, the apparent molar volume, V_ϕ, limiting apparent molar volume, V_ϕ^° and the slope, S_v, transfer volume, V_ϕ,tr^°, apparent molar compressibility, K_s,ϕ, limiting apparent molar compressibility, K_s,ϕ^° and the slope, S_k, transfer volume, V_ϕ,tr^°, transfer compressibility, K_s,ϕ,tr^°, limiting apparent molar expansivity, E_ϕ^°, Hepler’s constant, (∂²V_ϕ^°/dT²), Falkenhagen Coefficient, A, Jones–Dole coefficient, B and hydration number, n_H were calculated. The Gibbs free energies of activation of viscous flow per mole of solvent, Δμ₁^°numbersign and per mole of solute, Δμ₂^°numbersign, entropies, ΔS^° and enthalpies, ΔH^° of activation of viscous flow were also calculated and discussed in terms of transition state theory. The structure-making/breaking ability of the amino acid has also been discussed in terms of the sign of (∂²V_ϕ^°/dT²) and dB/dT. The results have been interpreted in terms of solute–solvent and solute–solute interactions in these systems

[en] Highlights: • Reports ultrasonic speed and viscosity of acetonitrile + alkyl acrylate mixtures. • The study provides estimation of excess properties of these mixtures. • Provides information on nature and relative strength of interactions in these media. • The scaled particle theory (SPT) is used to predict theoretical ultrasonic speed. • Viscosity data is correlated with various empirical and semi-empirical models. The ultrasonic speeds, u and viscosities, η of binary mixtures of acetonitrile with alkyl acrylate (methyl acrylate, ethyl acrylate, n-butyl acrylate and t-butyl acrylate) over the entire composition range were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K and at atmospheric pressure. From the experimental data, the excess isentropic compressibility, ${\kappa }_{\text{s}}^{\text{E}}$, excess ultrasonic speed, $u^{\text{E}}$, excess molar isentropic compressibility, $K_{\text{s,m}}^{\text{E}}$ and deviations in viscosity, $\mathrm{\Delta }\eta$ have been calculated. The partial molar isentropic compressibilities and excess partial molar isentropic compressibilities over whole composition range, partial molar isentropic compressibilities and excess partial molar isentropic compressibilities of the components at infinite dilution are calculated. The variation of these parameters is discussed in terms of molecular interactions in these mixtures. The viscosities of these mixtures were correlated using various models and the ultrasonic speeds of these mixtures were theoretically calculated using scaled particle theory and the results are compared with experimental values.

[en] The densities of binary mixtures of formamide (FA) with ethanol, 1-propanol, 1,2-ethanediol, and 1,2-propanediol, including those of pure liquids, over the entire composition range were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15)K and atmospheric pressure. From the experimental data, the excess molar volume, V_m^E, partial molar volumes, V-bar_m,1andV-bar_m,2, over the whole composition range and V-bar_m,1^oandV-bar_m,2^o at infinite dilution, and excess partial molar volumes, V-bar_m,1^EandV-bar_m,2^E, over the whole composition range and V-bar_m,1^oEandV-bar_m,2^oE at infinite dilution were calculated. The variation of these parameters with composition and temperature of the mixtures have been discussed in terms of molecular interaction in these mixtures. The observed trends in V_m^E values indicate the presence of specific interactions between FA and alkanol molecules. The V_m^E values follows the order: ethanol<1-propanol<1,2-ethanediol<1,2-propanediol. It is observed that the V_m^E values depend upon the number of hydroxyl groups and alkyl chain length in these alkanol molecules

[en] Highlights: • Study reports new density and speed of sound data of acetonitrile (ACN) + alkyl methacrylate binary mixtures. • Provides estimation of excess properties of ACN + alkyl methacrylate mixtures. • Provides information on nature of interactions in these mixtures. The densities, ρ, and speed of sound, u, of the binary mixtures of acetonitrile with alkyl methacrylates (methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, including those of pure liquids, over the entire composition range were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K and atmospheric pressure. Using the experimental data, the excess molar volumes, $V_{\text{m}}^{\text{E}}$, excess speeds of sound, $u^{\text{E}}$, excess isentropic compressibilities, ${\kappa }_{\text{s}}^{\text{E}}$ and excess molar isentropic compressibilities, $K_{\text{s,m}}^{\text{E}}$ have been calculated. The partial molar volumes and compressibilities and excess partial molar volumes and compressibilities of the components of the mixtures over the whole composition range; and at infinite dilution have also been calculated. The excess properties were correlated by the Redlich–Kister polynomial equations. The variations of these parameters with composition and temperature have been discussed in terms of intermolecular interactions prevailing in these mixtures.

[en] The densities of binary mixtures of acetonitrile (ACN) with formamide (FA), N,N-dimethylformamide (DMF), N-methylacetamide (NMA), and N,N-dimethylacetamide (DMA), including those of pure liquids, over the entire composition range were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K and atmospheric pressure. From the experimental data, the excess molar volume, V_m^E, and partial molar volumes, V-bar _m,1 and V-bar _m,2, were calculated over whole composition range. The variation of these parameters with composition and temperature of the mixtures has been discussed in terms of molecular interaction in these mixtures. The V_m^E values were found negative for all the mixtures and at each temperature studied, indicating the presence of specific interactions between ACN and amide molecules. The extent of negative deviations in V_m^E values follows the order: FA>NMA>DMA>DMF. It is observed that the V_m^E values depend upon the positions of methyl groups in these amide molecules

[en] Highlights: • Reports new density data of benzonitrile (BN) + alkyl methacrylate mixtures. • Reports new speed of sound data of BN + alkyl methacrylate mixtures. • Provides computation of excess properties of BN + alkyl methacrylate mixtures. • Shows the effect of alkyl chain length on physicochemical properties and their derived parameters. • Reduced excess molar volume approach was applicable to these mixtures. -- Abstract: Experimental measurements of densities and ultrasonic speeds for the binary mixtures of benzonitrile with methyl/ethyl/n-butyl methacrylates over the entire composition range were carried out in the temperature range 293.15 K–318.15 K and atmospheric pressure of 0.1 MPa. Using the experimental data, the excess molar volume, excess ultrasonic speed, excess isentropic compressibility, and excess molar isentropic compressibility have been calculated and correlated by Redlich-Kister equation. The partial molar and excess partial counterparts of molar volumes and molar compressibilities over the whole composition range; and at infinite dilution have also been calculated. The dependence of these parameters on composition and temperature has been interpreted in terms of intermolecular interactions prevailing in these mixtures. The order of interactions suggested by the excess functions is found to be MMA > EMA > BMA. The major cause of the order is the steric hindrance caused by alkyl group. The results showed the effect of varying chain length on excess functions and interactions of the system.

[en] Highlights: • Reports ρ, u and η data of α-amino acids in semicarbazide hydrochloride + water solutions. • Study elucidates interactions of amino acids with semicarbazide hydrochloride in aq. media. • Structure-making/-breaking tendency of α-amino acids in these media is investigated. • Thermodynamics of viscous flow has also been investigated. • Groups’ contributions of amino acids to various parameters have been calculated. -- Abstract: Various non-covalent interactions can be scrutinized by the measurement of physical properties. The nature of interactions between drugs and amino acids governs the functionalization process, so a better understanding demands reliable thermophysical data. Keeping this in mind, we report herein the densities, ρ, ultrasonic speed, u and viscosities, η of glycine, l-alanine, l-valine and l-isoleucine in aqueous-semicarbazide hydrochloride (1 wt% and 2 wt% semicarbazide hydrochloride in water) solvents in the temperature range of 293.15–318.15 K at an interval of 5 K and at atmospheric pressure. The density data have been used to calculate the apparent molar properties like V_ϕ, $V_{\varphi }^{°}$ and transfer volume, $V_{\varphi ,tr}^{°}$. From the ultrasonic speed data, thermo-acoustical parameters, such as $K_{s,\varphi }$, $K_{s,\varphi }^{°}$ and transfer compressibility, $K_{s,\varphi ,tr}^{°}$ have been evaluated. The viscosity data have been used to calculate Falkenhagen Coefficient, A, Jones-Dole coefficient, B. The hydration numbers, $n_{\text{H}}$ has also been evaluated. The entropies, $\mathrm{\Delta }{S}^{°\#}$ and enthalpies, $\mathrm{\Delta }{H}^{°\#}$ activation parameters, $\mathrm{\Delta }{\mu }_1^{°\#}$ and $\mathrm{\Delta }{\mu }_2^{°\#}$ were also calculated. The co-sphere overlap model was used to interpret the positive $V_{\varphi ,tr}^{°}$ values. In addition, the values of $V_{\varphi }^{°}$, $K_{s,\varphi }^{°}$, B and $\mathrm{\Delta }{\mu }_2^{°\#}$ have been split into groups’ contributions of the amino acids.

[en] Densities, ρ, ultrasonic speeds, u, and viscosities, η, of aqueous-1,4-butanediol (20% and 40% w/w of 1,4-butanediol) and of solutions of glycine (Gly), DL-alanine (Ala), and L-valine (Val) in aqueous-1,4-butanediol were measured at T = (298.15, 303.15, 308.15, 313.15, and 318.15) K. From these experimental results, apparent molar volume, V_φ, limiting apparent molar volume, V_φ⁰ and the slope, S_v, apparent molar compressibility, κ_φ, limiting apparent molar compressibility, κ_φ⁰, and the slope, S_k, transfer volume, V_φ,tr⁰, Falkenhagen coefficient, A, Jones-Dole coefficient, B, free energies of activation of viscous flow per mole of solvent, Δμ₁⁰ and per mole of solute, Δμ₂⁰ were calculated. The results are interpreted from the point of view of solute-solvent and solute-solute interactions in these systems. It has been observed that there exist strong solute-solvent interactions in these systems, which increase with rise in temperature. For the amino acids studied, the values of V_φ⁰ follow the order: Gly < Ala < Val, indicating that the increased hydrophobic/non-polar character of the side chain of these amino acids causes a reduction in electrostriction at the terminal charged groups. These amino acids act as structure-breakers in aqueous-1,4-butanediol solvents. The thermodynamics of viscous flow has also been discussed