Thermo Acoustic Parameters of Tetrabutylammonium Borate and Perchlorate in Non-Aqueous Solvents

Interactions of electrolytes in a binary mixture can be determined by various techniques. Ultrasonic velocity measurements prove to be one of the important tools for measuring various acoustic properties at variable temperature. Thermo acoustic parameters like Isentropic compressibility (κs),Acoustic impedance (Z), Free volume (Vf), Absorption coefficient (Abscoeff), Intermolecular free length (Lf), Gibb’s free energy (ΔG), Relaxation time (τ), Rao’s constant (Rm), Internal pressure (πi), Wada’s constant (w), and Entropy (H) for Tetrabutylammonium tetraphenylborate (Bu4NBPh4) and Tetrabuty lammonium perchlorate (Bu4NClO4) was calculated using experimental ultrasonic velocities, viscosities and densities at three different temperatures (298K, 308 K and 318K) and 1 atmospheric pressure in non-aqueous solvents like Dimethylsulfoxide (DMSO), Pyridine (Py) and their binary mixtures at 0, 20, 40, 60, 80 and 100 mol% of Py at variable temperatures ranging from 298K to 318K. Both Bu4NBPh4, Bu4NClO4, showed an increase in the ultrasonic velocity values at all the temperatures. This shows that molecular interactions are taking place in both the electrolytes. These increases in the molecular interactions with increase in the concentration of electrolytes in the solvent mixture were discussed in terms of solvent structural effects. And results showed the greater molecular interaction in DMSO rich regions.

Study of Molecular Interaction in Aqueous KCl at Different Temperatures

Ultrasonic velocity, density, viscosity, and electrical conductivity have been measured for an aqueous solution of KCl at different concentrations and temperatures, the frequency is maintained at a constant value. Using the above experimental data, parameters such as Rao's constant, Wada's constant, solvation number, and surface tension were calculated and the molecular interactions between molecules of KCl and water at different temperatures was studied. Using Walden's plot, the ionicity of the solution was also studied.

Effect of Ferroelectric Nano-powder on Electrical and Acoustical Properties of Cholesteric Liquid Crystal

Ferroelectric nano-materials are very sensitive to several external stimuli and have attracted great deal of attention due to their property of improving various properties such as photoluminescence, higher polarization, fast response time, low operating voltage and improved conductivity. For enhancing the physical properties, a proper selection of nano-materials for liquid crystals depends upon various factors such as size, shape, preparation methods, surfactant concentration and amount of doping materials. In the present study an attempt is made to study electrical and acoustical properties of cholesteric liquid crystal after dispersing ferroelectric nano-powder of Barium Titanate (BaTiO3). In addition with this particle size and surface area of pure and nono-particle dispersed liquid crystal were also measured. Our investigation shows increase in Rao’s constant or molar sound velocity, which indicates increase in molecular density indicating a close packing of the material. The measurement of dielectric relaxation at different frequencies gives information about the dynamics of polar groups and molecular motion.

Ultrasonic studies on temperature dependence of ion solvent interactions of ionic liquid 1-butyl-2,3- dimethylimidazolium chloride in aqueous solutions of tetra-n-butylammonium bromide at T = (298.15 to 313.15) K

The densities (ρ), and ultrasonic velocities (u) of 1-Butyl-2, 3-dimethylimmidazolium chloride,[bdmim]Cl in aqueous solutions of Tetra-n-butyl ammonium bromide over the complete range of concentrations has been calculated at different temperatures T= (298.15 to 313)K. Experimentally obtained values of ρ and u were used to calculate the parameters like acoustic impedance (Z), isentropic compressibility (βS), molar sound velocity (Rao’s constant) (R), molar compressibility (Wada’s constant)(W), intermolecular free length (Lf), co-efficient of thermal expansion (α), heat capacity ratio (γ), isothermal compressibility (βT) and nonlinearity parameters (B/A). The final results obtained were analyzed to understand the ion-solvent and ion-ion interaction so taking place in the solutions. Further, the effect of temperature on the ion solvent interactions was discussed. Ion-solvent interactions are affected by the thermo acoustical properties and by nonlinear parameters.

Ultrasonic study of molecular interactions in binary mixtures of methyl methacrylate(MMA) with toluene and dimethylacetamide at 318 K

<p>The ultrasonic velocity, density and viscosity at 318K have been measured in the binary systems of Methyl methacrylate + Toluene and Methyl methacrylate + Dimethylacetamide. In this work an attempt has been made for the first time to investigate the behavior of binary solutions of Methylmethacrylate(MMA) in Toluene and Dimethylacetamide(DMAC) with regard to acoustical parameters such as adiabatic compressibility(β), intermolecular free length(l_f), free volume(V_f), Rao’s constant(R), Wada’s constant(W) and specific acoustical impedance(Z) from ultrasonic measurements at 318 K were calculated. The results are interpreted in terms of molecular interaction between the components of mixtures.</p>

Acoustical Studies on Molecular Interaction of 1,3,4-Pyrazoline Derivatives Using Ultrasonic Technique at 303.15 K

The acoustical parameters for the binary liquid mixtures containing Pyrazoline derivatives in DMF have been estimated at 303.15 K, from the measured values of ultrasonic velocity (U), density (ρ) and viscosity (η). From these data some of acoustical parameters such as adiabatic compressibility (β), free length (Lf), acoustic impedance (Z), Rao’s constant (R), molar compressibility (W), relaxation time (τ), free volume (Vf) and internal pressure (πi), etc., have been computed using the standard relations. The results have been discussed in terms of molecular interactions.

Acoustical Studies of Some Synthesized Schiff Base Derivatives in Dimethylsulphoxide at 303.15 K, by Ultrasonic Velocity Measurement

The density, viscosity and sound velocity of five Schiff bases (1-5) derivatives in DMSO solutions have been studied at 303.15 K over a wide range of concentration. From these experimental data, some acoustical parameters such as Molar volume (Vm), Specific Acoustic Impedance (Z), Adiabatic compressibility (βad), Intermolecular Free Length (Lf), Rao’s Constant (R), Molar compressibility (W), Relaxation time(τ), van der Waals constant (b), Relaxation strength (r), Relative association (RA), Isothermal compressibility ( ) , Isothermal expansion co-efficient (α) ,Free volume (Vf) and Internal pressure (πi) and Ultrasonic attenuation (α/f²) have been evaluated. A fairly good correlation between a given parameter and concentration is observed. The results are interpreted in terms of molecular interactions like solvent-solvent, solvent-solute and solute-solute interactions.

Acoustical Studies of Binary Liquid Mixtures of p-Chlorotoluene in Benzene at Different Temperatures

Ultrasonic velocities (U), densities (ρ), and coefficient of viscosities (η) are measured for binary mixtures containing (i) p-chlorotoluene and (ii) benzene at 303.15 K, 308.15 K, 313.15 K and 318.15 K to understand the molecular interaction. Various acoustical parameters such as adiabatic compressibility (βad), free length (Lf), acoustic impedance (Z), free volume (Vf), molar volume (Vm), Rao’s constant (R), Wada’s constant (W) and internal pressure (πi), are calculated from the measured values of U, ρ, and η. The trend in acoustical parameters also substantiates to asses strong molecular interactions.

Acoustic parameter investigation of polyvinyl acetate with acetic acid using ultrasonic technique

Density, viscosity and ultrasonic velocity of polyvinyl acetate with acetic acid have been measured at a temperature of 299K for different concentrations. Density and viscosity have been measured for a binary liquid mixture with a specific gravity bottle and a viscometer. Ultrasonic velocity has been measured using a single crystal interferometer at a frequency of 2 MHz. Ultrasonic velocities for the binary mixture at 1 MHz and 2 MHz was compared by taking some values from the literature. The sound velocity (V), density (ρ) and viscosity (η) were used to calculate the parameters such as adiabatic compressibility (β), acoustic impedance (Z), intermolecular free length (Lf), ultrasonic attenuation (α/f2) and relaxation time (τ). The variations of experimentally obtained parameters indicate the presence of molecular interaction between the molecules of the mixture. The ultrasonic velocity increased with an increase in concentration. Solute-solvent interaction is further confirmed by viscosity values, which increased with increasing concentration suggesting more association between solute and solvent molecules. The linear variations in Rao’s constant and Wada’s constant suggest the absence of complex formation.

Ultrasonic Study of Molecular Interactions in Binary Mixtures at 303 K

The ultrasonic velocity, density and viscosity at 303 K have been measured in the binary systems of 1,4-dioxane and acetone with water. From the experimental data, various acoustical parameters such as adiabatic compressibility (β), intermolecular free length (Lf), free volume (Vf), internal pressure (πi), Rao’s constant (R), Wada’s constant (W) and specific acoustical impedance (Z) were calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures.