The Experts below are selected from a list of 5445 Experts worldwide ranked by ideXlab platform
V. P. Stepanov - One of the best experts on this subject based on the ideXlab platform.
-
Adiabatic Compressibility along the two phase saturation line for the molten lif cscl system
The Journal of Chemical Thermodynamics, 2019Co-Authors: V. P. StepanovAbstract:Abstract The Adiabatic Compressibility, β , of the immiscible liquid mixture (LiF + CsCl) along the saturation line was experimentally investigated in the temperature range from the melting point to the critical mixing temperature using sound velocity values, u , measured by the pulse method, and density quantities, ρ , determined using the hydrostatic weight procedure based on the relationship β = u −2 ρ −1 . The coefficients of the temperature dependencies for the Compressibility, sound velocity and density of the upper and lower equilibrium phases have opposite signs because of the superposition of the thermal motion intensity of the ions and the change in the phase compositions. The differences Δ β , Δ u and Δ ρ for the equilibrium phases decrease with temperature elevation. The temperature dependencies of the Compressibility, sound velocity and density difference are described using the empirical equations Δ β ≈ (T c − T) 1.004 , Δ u ≈ (T c − T) 1.003 and Δ ρ ≈ (T c − T) 0.504 .
-
Density and Adiabatic Compressibility of LiF + KBr Mixtures in the Two-Phase Region
High Temperature, 2019Co-Authors: V. P. StepanovAbstract:In this paper, we experimentally studied the Adiabatic Compressibility β of an exfoliating liquid mixture, LiF +KBr, on the saturation line in a temperature range from the melting point to the critical mixing temperature using the sound velocity u measured by the pulse method and the density ρ determined by hydrostatic weighing based on the ratio β = u–2ρ–1.The coefficients of the temperature dependences of the Compressibility and density of the upper and lower equilibrium phases are shown to have opposite signs due to the superposition of the thermal motion of ions and changes in the phase composition. The reduced differences β* and ρ* for the contacting phases decrease with decreasing reduced temperature T* in accordance with the empirical exponential equations β* ≈ T*1.017 and ρ* ≈ T* 0.494.
-
Ultrasonic Study of the Adiabatic Compressibility of Binary Molten Mixtures of Cesium Halides
Russian Journal of Physical Chemistry A, 2019Co-Authors: V. P. StepanovAbstract:Using the phase-time approach, the dependences of the speed of sound on the temperature and composition are measured in CsCl–CsBr, CsCl–CsI, and CsBr–CsI molten binary mixtures. The Adiabatic Compressibility of these mixtures is calculated from the experimental values of speed and density. Negative deviations from the additive values of the speed of sound and positive deviations from the additive values of Adiabatic Compressibility are observed. The magnitude of deviation depends on the ratio of the sizes of anions in the mixtures.
-
density and Adiabatic Compressibility of lif kbr mixtures in the two phase region
High Temperature, 2019Co-Authors: V. P. StepanovAbstract:In this paper, we experimentally studied the Adiabatic Compressibility β of an exfoliating liquid mixture, LiF +KBr, on the saturation line in a temperature range from the melting point to the critical mixing temperature using the sound velocity u measured by the pulse method and the density ρ determined by hydrostatic weighing based on the ratio β = u–2ρ–1.The coefficients of the temperature dependences of the Compressibility and density of the upper and lower equilibrium phases are shown to have opposite signs due to the superposition of the thermal motion of ions and changes in the phase composition. The reduced differences β* and ρ* for the contacting phases decrease with decreasing reduced temperature T* in accordance with the empirical exponential equations β* ≈ T*1.017 and ρ* ≈ T* 0.494.
-
Adiabatic Compressibility along the two-phase saturation line for the molten (LiF + CsCl) system
The Journal of Chemical Thermodynamics, 2019Co-Authors: V. P. StepanovAbstract:Abstract The Adiabatic Compressibility, β , of the immiscible liquid mixture (LiF + CsCl) along the saturation line was experimentally investigated in the temperature range from the melting point to the critical mixing temperature using sound velocity values, u , measured by the pulse method, and density quantities, ρ , determined using the hydrostatic weight procedure based on the relationship β = u −2 ρ −1 . The coefficients of the temperature dependencies for the Compressibility, sound velocity and density of the upper and lower equilibrium phases have opposite signs because of the superposition of the thermal motion intensity of the ions and the change in the phase compositions. The differences Δ β , Δ u and Δ ρ for the equilibrium phases decrease with temperature elevation. The temperature dependencies of the Compressibility, sound velocity and density difference are described using the empirical equations Δ β ≈ (T c − T) 1.004 , Δ u ≈ (T c − T) 1.003 and Δ ρ ≈ (T c − T) 0.504 .
Ronald E. Verrall - One of the best experts on this subject based on the ideXlab platform.
-
apparent molar volume and apparent molar Adiabatic Compressibility studies of anesthetic molecules in aqueous micelle solutions of ctab and ctac as a function of surfactant concentration and temperature
The Journal of Physical Chemistry, 1994Co-Authors: Luchun Wang, Ronald E. VerrallAbstract:Apparent molar volume and Adiabatic Compressibility properties of halothane and isoflurane in aqueous micelle solutions of hexadecyltrimethylammonium bromide (CTAB) and chloride (CTAC) have been studied as a function of surfactant concentration and temperature. Specific conductance measurements of the micellar systems in the presence and absence of the additive molecules were used to estimate the effect of the solubilized additives on the apparent degree of micelle dissociation. As well, 1 H T 1 relaxation and chemical shift studies of the micellized surfactant in the absence and presence of the additive were measured in an attempt to obtain complementary data regarding the solubilization sites of the additives in the micellar systems
-
apparent molar volume and apparent molar Adiabatic Compressibility studies of 2 6 di tert butyl 4 methylphenol and 2 tert butyl 4 methoxyphenol in aqueous micelle solutions of hexadecyltrimethylammonium chloride as a function of surfactant concentrat
Joint International Conference on Information Sciences, 1993Co-Authors: Luchun Wang, Ronald E. VerrallAbstract:Abstract Ultrasonic velocities and densities of aqueous solutions of cetyltrimethylammonium chloride have been measured at concentrations below 0.35 mol kg-1 at 25, 35, and 45°C. Apparent molar volume and apparent molar Adiabatic Compressibility properties of the aqueous surfactant solutions were derived from these data. Apparent molar volumes and apparent molar Adiabatic compressibilities of 2,6-di-tert-butyl-4-methylphenol and 2-tert-butyl-4-methoxyphenol dissolved in aqueous micellar solutions of cetyltrimethylammonium chloride were determined as a function of surfactant concentration and temperature. The results obtained for the binary and ternary systems are compared with those previously published for binary aqueous cetyltrimethylammonium bromide systems and for ternary systems of this surfactant containing the same additives. The degree of counterion dissociation from the micelles and the effect this has on the extent of hydration of the head group region of the micelle are shown to have an effect on the solubilization sites of hydrophobic-like additives in these micelles.
Dorota Kmiotek - One of the best experts on this subject based on the ideXlab platform.
-
ultrasonic velocity density and Adiabatic Compressibility for 2 6 dimethylpyridine water in the temperature range 293 318 k
Journal of Chemical & Engineering Data, 1996Co-Authors: Stefan Ernst, And Wojciech Marczak, Dorota KmiotekAbstract:Ultrasonic velocities and densities for 2,6-dimethylpyridine (1) + water (2) were measured over the entire composition range in the temperature interval 293−318 K. Using the Laplace formula, the Adiabatic Compressibility was calculated. The results and the empirical smoothing polynomials are presented. The density decreases monotonically with an increase of the amine concentration, while the velocity and Compressibility isotherms show two points of interest: a nearly common crossing point at a mole fraction x1 ≈ 0.03 and extrema at x1 ≈ 0.15.
-
Ultrasonic velocity, density, and Adiabatic Compressibility for 2,6-dimethylpyridine + water in the temperature range 293-318 K
Journal of Chemical & Engineering Data, 1996Co-Authors: Stefan Ernst, And Wojciech Marczak, Dorota KmiotekAbstract:Ultrasonic velocities and densities for 2,6-dimethylpyridine (1) + water (2) were measured over the entire composition range in the temperature interval 293−318 K. Using the Laplace formula, the Adiabatic Compressibility was calculated. The results and the empirical smoothing polynomials are presented. The density decreases monotonically with an increase of the amine concentration, while the velocity and Compressibility isotherms show two points of interest: a nearly common crossing point at a mole fraction x1 ≈ 0.03 and extrema at x1 ≈ 0.15.
Tsutomu Seimiya - One of the best experts on this subject based on the ideXlab platform.
-
stereochemical aspects of micellar properties of esterified glucoside surfactants in water apparent molar volume Adiabatic Compressibility and aggregation number
Colloid and Polymer Science, 2000Co-Authors: Kazuhiro Fukada, Tsutomu Seimiya, M Kawasaki, Yutaka Abe, M Fujiwara, K OhbuAbstract:The apparent molar volume and the apparent molar Adiabatic Compressibility of the sugar-based surfactants methyl 6-O-octanoyl-α-d-glucopyranoside (α-MOnG), methyl 6-O-octanoyl-β-d-glucopyranoside (β-MOnG), and octyl β-d-glucoside were measured over a wide concentration range. Also, the aggregation number of their micelles was determined from the Debye plot using static light scattering data. It was found that the micellar aggregation number for α-MOnG is 179 at 35 °C, which is 1.5 times larger than that for β-MOnG, suggesting that the anomerism of the head group influences the packing of the monomers during micelle formation.
-
Effect of pressure and temperature on Adiabatic Compressibility of aqueous solutions of amphiphiles with a perfluorocarbon chain
Thermochimica Acta, 2000Co-Authors: Kazuhiro Fukada, Masatoshi Fujii, Tadashi Kato, Yukihiro Kobayashi, Yoko Ota, Tsutomu SeimiyaAbstract:Abstract The apparent Adiabatic Compressibility and the apparent molar volume of sodium perfluoroheptanoate (C 6 F 13 COONa) were obtained from the experimental data of ultrasound velocity and density of its aqueous solutions at the concentration above and below CMC (critical micelle concentration) as functions of applied pressure (0–70 MPa) and temperature (5–35°C). Those were compared to the reported data for sodium decanoate (C 9 H 19 COONa) of Vikingstad et al. [J. Colloid Interface Sci. 72 (1979) 59]. It was found that the micelles of C 6 F 13 COONa were more easily compressible than C 9 H 19 COONa micelles under the condition studied. For the singly dispersed state below CMC, negative apparent Compressibility of C 6 F 13 COONa was confirmed and it approached to zero with the increase of pressure or temperature suggesting the decreased electrostriction and hydrophobic hydration with pressure or temperature rise.
-
Effect of Pressure on Adiabatic Compressibility of Aqueous Solutions of Decyltrimethylammonium Bromide
Journal of Colloid and Interface Science, 1995Co-Authors: Kazuhiro Fukada, Akihiro Oishi, Masatoshi Fujii, Toshiaki Shirakawa, Tadashi Kato, Tsutomu SeimiyaAbstract:Abstract The apparent Adiabatic Compressibility and the apparent molar volume of decyltrimethylammonium bromide (C 10 TAB) at 25°C were obtained from the experimental data of ultrasound velocity and density of its aqueous solutions at the concentration above and below CMC under the applied pressure ranging from 0 to 40 MPa by using the apparatus developed for this study. The application of pressure promoted hydrophobic hydration and decreased the micellar volume. It was found that isothermal Compressibility of the monomeric state of C 10 TAB derived from density data was appreciably larger than the estimated value based on the sound velocity data. It is supposed that the rearrangement of hydrated water could not follow the rapid periodic change of pressure by ultrasound and led to the lower Compressibility of C 10 TAB.
Luchun Wang - One of the best experts on this subject based on the ideXlab platform.
-
apparent molar volume and apparent molar Adiabatic Compressibility studies of anesthetic molecules in aqueous micelle solutions of ctab and ctac as a function of surfactant concentration and temperature
The Journal of Physical Chemistry, 1994Co-Authors: Luchun Wang, Ronald E. VerrallAbstract:Apparent molar volume and Adiabatic Compressibility properties of halothane and isoflurane in aqueous micelle solutions of hexadecyltrimethylammonium bromide (CTAB) and chloride (CTAC) have been studied as a function of surfactant concentration and temperature. Specific conductance measurements of the micellar systems in the presence and absence of the additive molecules were used to estimate the effect of the solubilized additives on the apparent degree of micelle dissociation. As well, 1 H T 1 relaxation and chemical shift studies of the micellized surfactant in the absence and presence of the additive were measured in an attempt to obtain complementary data regarding the solubilization sites of the additives in the micellar systems
-
apparent molar volume and apparent molar Adiabatic Compressibility studies of 2 6 di tert butyl 4 methylphenol and 2 tert butyl 4 methoxyphenol in aqueous micelle solutions of hexadecyltrimethylammonium chloride as a function of surfactant concentrat
Joint International Conference on Information Sciences, 1993Co-Authors: Luchun Wang, Ronald E. VerrallAbstract:Abstract Ultrasonic velocities and densities of aqueous solutions of cetyltrimethylammonium chloride have been measured at concentrations below 0.35 mol kg-1 at 25, 35, and 45°C. Apparent molar volume and apparent molar Adiabatic Compressibility properties of the aqueous surfactant solutions were derived from these data. Apparent molar volumes and apparent molar Adiabatic compressibilities of 2,6-di-tert-butyl-4-methylphenol and 2-tert-butyl-4-methoxyphenol dissolved in aqueous micellar solutions of cetyltrimethylammonium chloride were determined as a function of surfactant concentration and temperature. The results obtained for the binary and ternary systems are compared with those previously published for binary aqueous cetyltrimethylammonium bromide systems and for ternary systems of this surfactant containing the same additives. The degree of counterion dissociation from the micelles and the effect this has on the extent of hydration of the head group region of the micelle are shown to have an effect on the solubilization sites of hydrophobic-like additives in these micelles.
