Ultrasonic Velocity Studies Research Articles

Density, viscosity and ultrasonic velocity studies of cardo group containing symmetric double Schiff bases solutions at 303, 308 and 313 K

The density, viscosity and ultrasonic velocity (2 MHz) of pure solvents e.g. chloroform, DMF, 1,4-dioxane and symmetric double Schiff bases solutions have been investigated to understand the effect of solvents on molecular interactions at 303, 308 and 313 K. Various acoustical parameters such as U (ultrasonic velocity), Z (specific acoustical impedance), k s (isentropic compressibility), R (Rao's molar sound function), b (Van der Waals constant), π (internal pressure), V f (free volume), L f (intermolecular free path length), (α/f 2 ) Cl (classical absorption coefficient) and τ (viscous relaxation time) have been determined and correlated with concentration (C). Good to excellent correlation between a given parameter and concentration is observed at all temperatures (T) and solvent systems studied. Linear or non-linear increase or decrease of acoustical parameters with concentration and temperature indicated the existence of strong molecular interactions. The linear or non-linear increase of S n with C and decrease with T further supported the existence of molecular interactions.

Miscibility of polymethylmethacrylate and polyethyleneglycol blends in tetrahydrofuran

AbstractThe miscibility of polymethylmethacrylate (PMMA) and polyethyleneglycol (PEG) blends in tetrahydrofuran (THF) has been investigated by viscosity, density, refractive index, and ultrasonic velocity studies. Various interaction parameters such as polymer–solvent and blend–solvent interaction parameters and heat of mixing have been calculated using the viscosity, density, and ultrasonic velocity data. The results indicated the existence of positive interactions in the blend polymer solutions and that they are miscible in THF in the entire composition range. The study also revealed that variation in the temperature does not affect the miscibility of PMMA and PEG blends in THF significantly. The presence of hydrogen bonding in the blends in the solid state has also been indicated by FTIR studies. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Searching for post-perovskite transition in CaSnO3 at high pressure: an ultrasonic velocity study to 18 GPa

Compressional (P) and shear (S) wave velocities of CaSnO3 perovskite were measured at room temperature using ultrasonic interferometry up to 18 GPa. Discontinuities of the magnitude suggested in previous theoretical calculations are not observed in derived velocities over the entire experimental pressure range explored here. A least squares fitting of the P and S wave velocities to third-order finite strain equations yielded zero pressure adiabatic bulk and shear moduli and their first pressure derivatives, K=166(2) GPa, K′=5.4(2), G=88(1) GPa and G′=1.2(1). These results are in agreement with previous experiments, within mutual uncertainties. Examinations of the current data as well as comparison with previous measurements at lower pressures conclude the presence of a post-perovskite phase transition in CaSnO3 is not visible in the elasticity at ambient temperature within 0–18 GPa range.

Miscibility Studies on Chitosan/Poly(vinyl alcohol) Blends

Miscibility studies of chitosan (CHI)/poly(vinyl alcohol) (PVA) blend in buffer solution were carried out in several blend compositions (10/90, 20/80, … , 90/10). Viscosity, ultrasonic velocity, density and refractive were measured at 30, 40 and 50°C, respectively. Using viscosity data, the interaction parameters μ and thermodynamic parameter α were computed to determine the miscibility of the blend in solution. These values revealed that the blend is miscible when the chitosan content is more than 60% in the blend. The obtained results were further confirmed by the ultrasonic velocity, density and refractive index study.

Density, viscosity and ultrasonic velocity studies of aqueous solutions of sodium acetate at different temperatures

The densities and viscosities of aqueous solutions of sodium acetate have been measured at 298.15, 303.15, 308.15 and 313.15 K and at atmospheric pressure. The molality range has been studied between 6.09 × 10 − 2 to 7.314 × 10 − 1 mol kg − 1. The experimental values of density have been used to calculate apparent molar volume, partial molar volume, solute–solute interaction parameter, and Hepler's constant. The viscosity data have been analyzed with Jone–Dole equation. Furthermore, ultrasonic velocity measurements of aqueous solutions of sodium acetate have been made at 298.15 and 308.15 K and at atmospheric pressure. From experimental values of ultrasonic velocity, apparent molar isentropic compressibility and limiting apparent molar isentropic compressibility have been calculated. All the parameters calculated from density, viscosity, and ultrasonic velocity indicate that the sodium acetate is water structure maker.

Impact of cosolvents (polyols) on globular protein functionality: Ultrasonic velocity, density, surface tension and solubility study

The objective of this study was to understand how cosolvents influence the molecular and functional properties of globular proteins in aqueous solutions. The ultrasonic velocity, density and adiabatic compressibility of cosolvent solutions (0–50 wt% sorbitol or glycerol) were measured in the absence and presence of a globular protein (1 wt% β-lactoglobulin) at 30 °C. These measurements were used to calculate the partial specific apparent volume and adiabatic compressibility of the protein. The protein's volume decreased and its compressibility increased in the presence of high cosolvent concentrations, which were attributed to changes in the properties of the protein interior and solvation layer. Sorbitol was more effective than glycerol at decreasing the protein volume at high cosolvent concentrations, which may be because glycerol has some surface activity and may therefore accumulate around hydrophobic regions on the protein surface. Our data were used to account for the observation that sorbitol is more effective than glycerol at increasing the thermal stability and self-association of the β-lactoglobulin. A better understanding of the influence of protein–cosolvent–solvent interactions on the functionality of globular proteins may facilitate the design of protein-based products.

Densities, viscosities and ultrasonic velocity studies of binary mixtures of toluene with heptan-1-ol, octan-1-ol and decan-1-ol at 298.15 and 308.15 K

Densities, viscosities and ultrasonic velocities of binary mixtures of toluene with heptan-1-ol, octan-1-ol and decan-1-ol have been measured over the entire range of composition at (298.15, and 308.15) K and at atmospheric pressure. From the experimental values of density, viscosity and ultrasonic velocity, the excess molar volumes ( V E), deviations in viscosity (Δ η) and deviations in isentropic compressibility (Δ κ s) have been calculated. The excess molar volumes, deviations in viscosity and deviations in isentropic compressibility have been fitted to the Redlich–Kister polynomial equation.

Ultrasonic studies on polymer blend (natural/synthetic) in strong electrolyte solutions

Ultrasonic velocity studies were carried out in the waste mulberry silks (M.W 475) viz., CSR4 and CSR2 at 0.004% concentration in sodium hydroxide (NaOH) and potassium hydroxide (KOH) solutions, the concentration of synthetic polymer polyethylene glycol (PEG) (M.W 6000) was varied to understand the nature of solute–solvent interactions in the natural/synthetic polymer in strong electrolytes.

Compressibility studies of tetraalkylammonium salts in binary mixtures of dimethysulfoxide and acetone

Present work reports the results of ultrasonic velocity studies of tetrabutylammoniumtetraphenyl boride Bu 4NBPh 4, tetrapropylammonium iodide Pr 4NI, tetrabutylammonium iodide Bu 4NI, tetrapentylammonium iodide Pen 4NI and sodium tetraphenyl boride NaBPh 4 in binary mixtures of DMSO and Ac. Adiabatic compressibility coefficient, β and corresponding limiting molar adiabatic compressibility, ϕ κ o(s) of R 4NI salts are noted to decrease with the decrease in the size of hydrophobic group. This observation is suggested to be of relevance to the reorganizing of solvent molecules at the hydrocarbon–solvent interface, and not to direct solute–solvent interaction. The variation in ϕ κ o(s) with solvent composition, although reflects the contribution due to intermolecular interaction, insensitivity of solvent composition dependence of limiting ionic molar compressibility ϕ κ o(i) and its sign for Pen 4N +, Bu 4N +, Pr 4N +and Ph 4B − indicate their poor solvation behaviour. ϕ κ o(i) < 0 for Na + and I − on the contrary, is suggested to support the solvation effect of these ions.

Miscibility studies on chitosan/hydroxypropylmethyl cellulose blend in solution by viscosity, ultrasonic velocity, density, and refractive index methods

AbstractThe miscibility studies of chitosan (CHI)/hydroxypropylmethyl cellulose (HPMC) blend in buffer solution (0.1M acetic acid + 0.2M sodium acetate) were carried out by viscosity, ultrasonic velocity, density, and refractive index methods at 30, 40, and 50°C, respectively. Using viscosity data, the interaction parameter μ and α were computed. These values revealed that the blend is miscible when the CHI content is more than 50% in the blend. The obtained results were further confirmed by ultrasonic velocity, density, and refractive index study. And also the result revealed that the change in temperature has no significant effect on the miscibility of CHI/HPMC polymer blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2738–2742, 2006

Densities, Viscosities, and Ultrasonic Velocity Studies of Binary Mixtures of Chloroform with Octan-1-ol and Decan-1-ol at (303.15 and 313.15) K

Densities, viscosities, and ultrasonic velocities of binary mixtures of chloroform with octan-1-ol and decan-1-ol have been measured over the entire range of composition at (303.15 and 313.15) K and at atmospheric pressure. From the experimental values of density, viscosity, and ultrasonic velocity, the excess molar volumes VE, deviations in viscosity Δη, and excess isentropic compressibility have been calculated. The excess molar volumes and excess isentropic compressibility are positive for both the binaries studied over the whole composition, while deviations in viscosities are negative for both the binary mixtures. The excess molar volumes, deviations in viscosity, and deviations in isentropic compressibility have been fitted to the Redlich−Kister polynomial equation. The very recently proposed Jouyban−Acree model is used to correlate the experimental values of density, viscosity, and ultrasonic velocity at different temperatures.

Densities, viscosities, and ultrasonic velocity studies of binary mixtures of trichloromethane with methanol, ethanol, propan-1-ol, and butan-1-ol at T = (298.15 and 308.15) K

Densities, viscosities, and ultrasonic velocities of binary mixtures of trichloromethane with methanol, ethanol, propan-1-ol, and butan-1-ol have been measured over the entire range of composition, at (298.15 and 308.15) K and at atmospheric pressure. From the experimental values of density, viscosity, and ultrasonic velocity, the excess molar volumes ( V E), deviations in viscosity (Δ η), and deviations in isentropic compressibility (Δ κ s) have been calculated. The excess molar volumes, deviations in viscosity and deviations in isentropic compressibility have been fitted to the Redlich–Kister polynomial equation. The Jouyban–Acree model is used to correlate the experimental values of density, viscosity, and ultrasonic velocity.

Solution and solid‐state blend compatibility of poly(vinyl alcohol) and poly(methyl methacrylate)

AbstractThe blend miscibility of poly(vinyl alcohol) and poly(methyl methacrylate) in N,N′‐dimethylformamide solution was investigated by viscosity, density, ultrasonic velocity, refractive index, and UV and fluorescence spectra studies. Differential scanning calorimetry and scanning electron microscopy were used to confirm the blend miscibility in the solid state. Blends were compatible when the concentration of poly(vinyl alcohol) was greater than 60 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2415–2421, 2006

Densities, Viscosities, and Ultrasonic Velocity Studies of Binary Mixtures of Chloroform with Pentan-1-ol, Hexan-1-ol, and Heptan-1-ol at (303.15 and 313.15) K

Densities, viscosities, and ultrasonic velocities of binary mixtures of chloroform with pentan-1-ol, hexan-1-ol, and heptan-1-ol have been measured over the entire range of composition at (303.15 and 313.15) K and at atmospheric pressure. From the experimental values of density, viscosity, and ultrasonic velocity, the excess molar volumes (V E), deviations in viscosity (Δη), and excess isentropic compressibility (κsE) have been calculated. The excess molar volumes (V E) are positive for all the three binaries studied over the whole composition, the excess isentropic compressibilities (κsE) are also positive except for low mole fractions of chloroform, while deviations in viscosities (Δη) are negative for all the three binary mixtures. The excess molar volumes, deviations in viscosity, and excess isentropic compressibility have been fitted to the Redlich−Kister polynomial equation. McAllister's three-body interaction model has been used to correlate the kinematic viscosities of binary liquid mixtures with ...

Ultrasonic studies on aqueous polyethylene oxide in n-alkanols

Ultrasonic velocity, density and viscosity studies were undertaken to study the influence of n-alkanols (butan-1-ol, petan-1-ol and hexan-1-ol) on aqueous PEO (1%) solution at 303 K. From the observed values, the related acoustical parameters are calculated and their variations are discussed in light of molecular interaction of n-alkanols in aqueous polyethylene oxide solution.

Densities, Viscosities, and Ultrasonic Velocity Studies of Binary Mixtures of Chloroform with Propan-1-ol and Butan-1-ol at (303.15 and 313.15) K

Densities, viscosities, and ultrasonic velocities of binary mixtures of chloroform with propan-1-ol and butan-1-ol have been measured over the entire range of composition, at (303.15 and 313.15) K and at atmospheric pressure. From the experimental data, excess molar volumes (V E), deviations in viscosity (Δη), and excess isentropic compressibility ( ) have been calculated. The excess molar volumes and isentropic compressibility for propan-1-ol and butan-1-ol are positive while deviations in viscosity are negative. The results have been interpreted in terms of intermolecular interactions. These are further fitted to the Redlich−Kister polynomial equation.

Ultrasonic studies on drug release pattern from different ethylcellulose bases

Ultrasonic velocity and absorption studies have been carried out on the drug erythromycin estolate added to different bases viz., ethylcellulose/polyethylene glycol (EC/PEG), ethylcellulose/hydroxypropyl methylcellulose (EC/HPMC) and ethylcellulose/eudrajit (EC/EUD). The elastic properties of the different bases with and without drug are estimated and an overall view about the drug release pattern is given.

Ultrasonic velocity and absorption studies on different phthalates

The ultrasonic velocity and absorption values of pure dimethyl, diethyl and dibutyl phthalates are determined at four different temperatures. The measured data are used to compute some acoustical parameters and thermodynamic parameters. These parameters are used to discuss the nature and the extent of intermolecular interactions in the samples.

Ultrasonic studies of the binary mixtures of ethyl acetate and cresols—application of Kosower and Dimroth treatments

The ultrasonic velocity ( ν) studies were carried out at a frequency of 2 MHz (transducer of x-cut quartz crystal) using ultrasonic pulse echo system (model UX4400-M) on cresols in ethyl acetate at constant temperature of 311 K. The values of internal pressure ( π i) and molar free volume ( V f) were calculated from measured values of ultrasonic velocity ( ν), viscosity ( η) and density ( ρ). An attempt is made to rationalize the ultrasonic velocity ( ν), internal pressure ( π i) and free volume ( V f) of binary mixtures using Kosower solvent parameter ( Z), Dimroth solvent parameter ( E T) and Dielectric constant ( ∈). It is found that there is linear correlation between ultrasonic velocity and acidity constant pk −1 a, indicating the dependence of acidity. Correlation of Ksower and Dimroth parameters with ultrasonic velocity confirms that solvent polarity is an important factor in the variation of ultrasonic velocity in the present investigation.

Interrelation of antiferrodistortive and ferroelectric phase transitions in Sr1−xAxTiO3 (A=Ba, Pb)

A dielectric and ultrasonic velocity study of antiferrodistortive and ferroelectric phase transitions in Sr1−xAxTiO3 (A=Ba, Pb) is reported. It is shown that both phase transitions co-exist at x<0.03 but at the higher concentration the ferroelectric phase transition entirely suppresses the antiferrodistortive phase transition. The experimentally obtained phase diagrams are discussed in the framework of the Landau phenomenological theory.