Thermo-acoustical Parameters Research Articles

Density, Viscosity, Sound Speed, and Thermoacoustical Parameters of Benzaldehyde with Chlorobenzene or Nitrobenzene at 303.15 K, 308.15 K, and 313.15 K

The values of the density, viscosity, and speed of sound for binary liquid mixtures of benzaldehyde with chlorobenzene or nitrobenzene have been measured over the entire range of composition at (303.15, 308.15, and 313.15) K. These values have been used to calculate the excess molar volume (\(V^\mathrm{E}\)), and excess free volume (\(V_\mathrm{f}^\mathrm{E}\)). McAllister’s three-body interaction model is used for correlating the kinematic viscosity of binary mixtures. The thermophysical properties (density, viscosity, and ultrasonic velocity) under study were fit to the Jouyban–Acree model.

Thermo-acoustic investigation in alcohol–water mixtures: Impact of lipophilic antioxidant on anionic surfactant properties for potential cosmeceutical application

In this present study, the self aggregation and solution properties of sodium dodecyl sulfate (SDS) in presence of lipophilic organic molecule i.e. butylatedhydroxyanisole (BHA) has been assessed by using simple and easily controlled approach to obtain CMC values and thermo-acoustic parameters via specific conductance (κ), viscosity (η), compressibility coefficient (β), apparent molar volume (ϕv) and apparent molar adiabatic compression (ϕk) at three different temperatures (25, 30, and 35°C). Taking into account the advantages of surfactant micelles as carriers, the basic impact and association of BHA on SDS micellar system has been studied in alcohol+water mixtures. It would therefore be interesting to evaluate the type of interaction between the moieties in order to design such surfactant aided immobilized system for better inhibitory action of BHA which could prove valuable to pharmaceutical or cosmeceutical industries.

Excess parameters for binary mixtures of ethyl benzoate with 1-propanol, 1-butanol and 1-pentanol at T=303, 308, 313, 318, and 323 K

Various thermo–acoustic parameters, such as excess isentropic compressibility (KsE), excess molar volume (VE), excess free length (LfE), excess Gibb's free energy (ΔG*E), and excess Enthalpy (HE), have been calculated from the experimentally determined data of density, viscosity and speed of sound for the binary mixtures of ethyl benzoate+1-propanol, or +1-butanol, or +1-pentanol over the entire range of composition at different temperatures (303, 308, 313, 318 and 323K). The excess functions have been fitted to the Redlich–Kister type polynomial equation. The deviations for excess thermo–acoustic parameters have been explained on the basis of the intermolecular interactions present in these binary mixtures.

Spectroscopic and ultrasonic studies on the hydrogen bonded complexes of aromatic aldehydes with phenol in hexane medium

The molecular interactions have been studied in the ternary systems of phenol with three structurally different aromatic aldehydes, viz., benzaldehyde, cinnamaldehyde and salicylaldehyde in n-hexane medium, through the behavior of measured ultrasonic velocity ‘u’, density ‘ρ’, dynamic viscosity ‘η’ and the calculated acoustic parameters at 303.15K and at atmospheric pressure. Excess thermo acoustic parameters reveal the existence of hydrogen bonded complexes between aldehydes and phenol. The variation of the excess parameters both in sign and magnitude within the range of concentration investigated is also discussed in terms of structural aspect and functional groups of the components involved. The existence of solute interactions is also confirmed through electronic absorption spectra with Benesi–Hildebrand theory at 303.15K. The formation constants of the donor and acceptor complexes determined both by spectroscopic and ultrasonic methods are comparable and follow similar trend. The trend in the formation constants is discussed based on structures of the component molecules in terms of field effects.

Study of miscibility and interaction in polyvinyl chloride-polyvinyl acetate blend using ultrasonic technique

The propagation of ultrasonic waves and the measurement of their velocity in solutions form an important tool for the evaluation of various acoustical and thermo dynamical parameters which give an insight into the nature of miscibility and molecular interactions in polymer blend. In the present investigation, ultrasonic velocities, densities and viscosities have been measured in 0.1M solution of polyvinyl chloride in tetrahydrofuran using pulse echo overlap technique at 298K at different concentrations of polyvinyl acetate. Thermoacoustical parameters such as adiabatic compressibility, molar sound velocity, molar compressibility, expansion coefficient, acoustic impedance, van der Waals' constant and internal pressure have been computed from the experimental data. The variation of ultrasonic velocity and other thermo-acoustical parameters shows nonlinear increase or decrease with molar concentration which suggest immiscibility or semi compatibility among the component polymers. Two immiscible polymers are need to be compatibilized in order to be used in commercial applications. The nature of solvent-polymer-polymer interaction and the effect of concentration on the molecular interaction of polyvinyl chloride and polyvinyl acetate in tetrahydrofuran have been studied.

Effect of temperature on thermoacoustic properties of olive oil in alcohol mixtures

The ultrasonic studies in liquids are great use in understanding the nature and strength of molecular interactions. Recently ultrasonic is the rapidly growing field research, which has been used in the food industry for both analysis and modification of food products. This paper presents ultrasonic velocity, density, adiabatic compressibility in olive oil with alcohol at different concentration that has been measured in the temperature range from 283.15K to 298.15K. The Moelwyn-Hughes parameter has been utilised to establish some simple relations between the available volumes, Bayer's non- linearity parameter, internal pressure, van der Waal's constant, Debye temperature etc. a relationship among the isobaric, isothermal and isochoric thermo-acoustical parameter have been studied and analyzed in the case olive oil with alcohol mixture. The present treatments had the distinct advantages of the thermo-acoustic parameters in the particular mixture.

Acoustical Studies of L-leucine and L-asparagine in aqueous electrolyte through thermal expansion coefficient

Amino acids are the building blocks of the proteins; their study provides important information, about the behaviour of larger biomolecules such as proteins. The properties of proteins such as their structure, solubility, denaturation, etc. are greatly influenced by electrolytes. Ultrasonic velocity and density values have been used for evaluation of thermal expansion coefficient and adiabatic compressibility for ternary systems (amino acid/salt + water) namely L-leucine / L-asparagine each in 1.5 M aqueous solution of NaCl used as solvent for various concentrations and at different temperatures (298.15K – 323.15K). Present paper reports the variation of various thermoacoustical parameters such as Moelwyn-Hughes parameter (C1), Beyer's non-linearity parameter (B/A), internal pressure (Pi), fractional free volume (f), available volume (Va), repulsive exponent (n), molecular constant (r), van der Waals' constant (b), Debye temperatue (θD), etc. have been computed from the thermal expansion coefficient with the change of concentration and temperature. The variations of all these parameters have been interpreted in terms of various intermolecular interactions such as strong, weak, charge transfer, complex formation, hydrogen bonding interaction. The structure making and breaking properties of the interacting components existing in proposed ternary systems. It shows the associating and dissociating tendency of the molecules of solute in solvent.The hetromolecular interactions are present in both the ternary systems.

Studies on thermo-acoustic parameters in the dilute solutions of poly(ethyleneglycol)

Ultrasonic velocities and densities have been measured for the dilute solutions of poly(ethylene glycol) of average molecular mass 400 g mol−1 in benzene at different temperatures between 299 and 328 K. The experimental data have been used to compute the thermo-acoustical parameters namely isentropic compressibility (β), intermolecular free length (L f), molar volume (V m), Schoff’s available volume (V a(s)), acoustic impedance (Z), molar sound velocity (R a), and molar compressibility (W). Variation of these parameters with temperature of the sample and mole fraction of the solute in the solution, keeping one of the either constant has been discussed to collect the informations on molecular structure and intermolecular interactions.

STUDY OF THERMODYNAMICAL PROPERTIES OF POLYVINYL ACETATE IN TETRAHYDROFURAN

The propagation of ultrasonic waves and the measurement of their velocity in solutions form an important tool for the evaluation of various acoustical and thermodynamical parameters which give an insight into the nature of miscibility and molecular interactions in polymer solutions. In the present study, the ultrasonic velocity, density, viscosity measurements have been made in 0.1 M solution using pulse echo overlap technique at 293 K at the different concentrations of polyvinyl acetate in tetrahydrofuran. Thermo-acoustical parameters viz., adiabatic compressibility, molar sound velocity, molar compressibility, expansion coefficient, acoustic impedance, van der Waals' constant and internal pressure have been computed from the experimental data. The nature of polymer/solvent interaction and the effect of concentration on the molecular interaction are studied. The nonlinear variations of polyvinyl acetate in tetrahydrofuran have been studied. The variation of ultrasonic velocity and other thermo-acoustical parameters shows nonlinear increase or decrease with molar concentration which suggest semi-compatibility of the polymer in the given solvent.

Acoustical and Thermodynamical Properties of Ternary Liquid Mixtures at 303.15 K

The observed experimental parameters such as density ( �), viscosity ( �) and ultrasonic velocity (U) of ternary liquid mixtures of primary alkanols such as 1-propanol, 1-butanol, 1-pentanol and 1-hexanol with N-N dimethylfomamide (DMF) in acetophenone at 303.15 K were determined. The observed experimental data have been utilized to evaluate some of the thermo acoustical parameters and also their excess values such as adiabatic compressibility ( � E ), intermolecular free length (L f E ), free volume (V f E ), internal pressure ( �i E ), Gibb's energy ( �G E ) and viscosity ( � E ). Our present investigation observes that the interaction between DMF (Proton acceptor) and 1-alkanols is due to hydrogen bonding. There seems to be a dissociation of associated structure of 1-alkanols and decrease in interaction (hydrogen bonding) between acetophenone and 1-alkanols on further addition of DMF. It is also noticed that on further addition of DMF leads to subsequent decrease in interaction between ketone (acetophenone) and 1-alkanols as well as between DMF and 1-alkanol, which eventually resulting in existence of weak molecular interactions in the present system of liquid mixtures.

Impact of cosolvent (glucose) on the stabilization of ovalbumin

Proteins are stabilized by glucose against denaturation due to extremes of pH. This was studied by means of density, ultrasonic velocity, viscosity and surface tension measurements in the ovalbumin (5 mg/ml) dissolved in phosphate buffer (pH 2, 5, 7, 9 and 12). Few thermo-acoustical parameters such as adiabatic compressibility, intermolecular free length, acoustic impedance, the partial apparent specific volume and the partial apparent specific adiabatic compressibility were calculated for the said systems. Obtained results suggest that the stabilization of ovalbumin occurs in the presence of glucose through strengthening of hydrophobic interactions supported by other non-covalent interactions and the steric exclusion effect of the cosolvent molecules.

Studies on molecular interactions in different solvent extractants with n-butanol at temperature 303.15 K: A thermoacoustic investigation

The ultrasonic velocities and densities of binary mixtures of different phosphinic acids (Cyanex 272, Cyanex 301, Cyanex 302) with n-butanol were measured over the whole mole fraction range at temperature 303.15K and at atmospheric pressure. Various thermo-acoustic parameters and their excess values have been evaluated from these measured values. The non-linear variations of such parameters with mole fractions of different phosphinic acids have been discussed in the light of inter-molecular interaction. Besides, a comparison study has been made between the experimentally obtained velocities and theoretically estimated velocities.

Effect of concentration on thermo acoustic and nonlinearity parameters (B/A) of barium chloride solutions in glycol–water mixtures at 303.15 K

Ultrasonic speed (U) and density (ρ) values for BaCl2.solutions are presented in 10%, 20%, and 30% glycol+water mixtures at 303.15K. The thermo acoustic parameters like isentropic compressibility (βs), isothermal compressibility (βT) and coefficient of thermal expansion (α) have been calculated for different solutions. The experimental values of sound speed have been fitted on Ballou's and Hartmann's equation for nonlinearity parameters and the variation of these parameters with the concentrations of solute in different solutions has been discussed in the context of ion–solvent interactions.

Influence of temperature on thermodynamic properties of acid–base liquid mixtures

Ultrasonic velocity, u density, ρ and viscosity, η of mixtures of N,N-dimethyl acetamide with equimolar mixture of ethanol + isopropyl alcohol/isobutyl alcohol/isoamyl alcohol, including those of pure liquids over the entire composition have been measured at T = 308.15, 313.15, and 318.15 K. Using this data, various thermo-acoustic parameters such as deviations in ultrasonic velocity, ∆u, isentropic compressibility, ∆k s , viscosity, Δη, excess molar volume, $$ V_{\text{m}}^{\text{E}} $$ and excess Gibb’s free energy of activation for viscous flow, ΔG *E have been calculated at different temperatures. The calculated deviation and excess functions have been fitted to the Redlich–Kister type polynomial equation. The influence of temperature on the observed negative and positive values of deviation and excess thermodynamic properties has been explained in terms of molecular interactions present in the investigated acid–base liquid mixtures. The experimental data of ultrasonic velocity have been used to check the applicability of velocity models of Nomoto, Van Dael and Vangeel and Junjie and viscosity data have also been availed to test the applicability of standard viscosity models of Grunberg-Nissan, Hind-Mc Laughlin, and Katti-Chaudhary for all the systems investigated at various temperatures.

Experimental Investigations on Ultrasonic Velocity and Behavior of Thermodynamic Parameters of Four Members of nO.m Series

Ultrasonic velocity measurements are carried out on fournOmcompounds viz., N-(p-n-methoxy and ethoxy benzylidene)-p-n-dodecyl and tetradecyl anilines, 1O.12, 1O.14, 2O.12 and 2O.14. The first three compounds exhibit mono variant nematic phase while the last compound exhibits nematic and smectic-A phases with variable thermal ranges. The temperature dependence of sound velocity, U shows minima at the isotropic-nematic and nematic-smectic-A transitions. In conjunction with the density data of these compounds, the thermo acoustic parameters such as adiabatic compressibility (βad), the molar sound velocity (Rao’s number) (Rn), molar compressibility (W), molecular free length (Lf) and available volume (Va) are estimated. In addition the intermolecular free length (Lf) is estimated in three different ways employing density and ultrasonic velocity data. The results are compared with the data available in literature of other compounds.

Ultrasonic and spectroscopic studies on hydrogen bonded complexes of aromatic amine and aryl ketones in n-hexane at 303.15 K

Viscometric and ultrasonic studies have been carried out in n-hexane solutions, containing equimolar concentration from 0.02 to 0.2 M of aromatic ketones and N-methylaniline (NMANI), at 303.15 K and at atmospheric pressure. The ketones studied in the present investigation are acetophenone (ACP), 4-chloroacetophenone (ClACP) and 4-methylacetophenone (MACP). The behaviour of measured ultrasonic velocity (u), density (ρ) and viscosity (η) and also the computed acoustic parameters provide strong evidence for the presence of strong solute–solute interactions in the three ternary systems. Excess molar volume and excess thermo acoustic parameters reveal the existence of hydrogen bonded complexes between the solute molecules, ketones and secondary amine. The variation of these parameters with the concentration shows that the existing interactions are influenced by the structure of components and functional groups of the components involved. An attempt has been made to confirm the formation of 1:1 complexes in these systems through UV–visible spectroscopic method at 303.15 K. The calculated values of formation constants of the charge transfer complexes both by acoustic and optical methods agree satisfactorily. The variation in the values of formation constant reveals that electron releasing substituent in the acetophenone molecule enhances the stability while electronegative substituent decreases the stability of the complex. The negative values of free energy of formation of these three complexes indicate that these complexes are thermodynamically stable.

Ultrasonic and optical studies on charge transfer complexes of p-chloranil with certain aromatic hydrocarbons in DMSO at 303.15 K

Ultrasonic investigation has been carried out on six ternary systems to establish the complex formation between p-chloranil (acceptor) and six aromatic hydrocarbons (donors), namely, benzene, toluene, o-xylene, m-xylene, p-xylene and mesitylene in DMSO medium at 303.15 K and at atmospheric pressure. Studies were carried out in the concentration range of 0.002 to 0.02 M of acceptor and donor with equimolar concentration of the two components in solution. The trend in the acoustical parameters and magnitude of excess thermo acoustical parameters has been used to identify the existence of strong intermolecular interaction through charge transfer complex formation. The formation of 1:1 complex was also confirmed by UV–Visible spectroscopic method at 303.15 K in these systems. It may be pointed out that the formation constants of the charge transfer complexes determined by Benesi–Hildebrand (spectroscopic) and Kannappan (ultrasonic) methods show similar trend and well establish the influence of structural aspect of the donor aromatic compounds on the stability of charge transfer complexes.

Excess parameters of binary mixtures of anisaldehyde with o-cresol, m-cresol and p-cresol at T = (303.15, 308.15, 313.15, and 318.15) K

The density, ultrasonic velocity, and viscosity of binary mixtures of (anisaldehyde+o-cresol, or +m-cresol, or +p-cresol) have been measured over the entire range of composition at T=(303.15, 308.15, 313.15, and 318.15)K. Using these data, various thermo-acoustic parameters such as deviation in adiabatic compressibility, Δβ, excess molar volume, VE, viscosity deviation, Δη and excess Gibb’s free energy of activation for viscous flow, ΔG∗E have been calculated. The calculated deviation and excess functions have been fitted to the Redlich–Kister polynomial equation. The negative and positive values of deviation or excess thermo-acoustic parameters observed have been explained on the basis of the intermolecular interactions present in these mixtures.

A Temperature Variant Thermo-Acoustical Approach for Computation of Excess Non-Linearity Parameter and Available Volume of Binary Liquid Mixtures

Thermoacoustical parameters have been computed for a binary system of cyclohexane + cyclohexanol at three different temperatures. These parameters have been employed to compute available volume by using two different approaches, thermoacoustical and ultrasonic. Furthermore non-linearity parameter, B/A, has also been computed by four different approaches. The excess counterparts of the non-linearity parameter have also been computed. A Comparative study has then been carried out which might shed some light on the molecular interactions.

Densities, Excess Molar Volumes, Ultrasonic Speeds, and Isentropic Compressibilities of Hexan-1-ol with 1,2-Dichloroethane, 1,2-Dibromoethane, and 1,1,2,2-Tetrachloroethene at (293.15 and 298.15) K

Densities, ρ, and ultrasonic speeds, u, of binary mixtures of hexan-1-ol with 1,2-dichloroethane, 1,2-dibromoethane, and 1,1,2,2-tetrachloroethene have been measured over the entire range of composition at (293.15 and 298.15) K and atmospheric pressure. From these data, the excess molar volumes, V E, deviations of ultrasonic speed, u D, from the ultrasonic speed of an ideal mixture, excess molar isentropic compressibilities, $${\kappa_{S,{\rm m}}^{\rm E}}$$ , intermolecular free lengths, L f, mean molecular radii, r, and thermal expansion coefficients, α, have been calculated. The experimental ultrasonic speeds have been analyzed in terms of Nomoto’s, Van Dael’s ideal mixture, and Junjie relations; Jacobson’s free length and Schaaffs’ collision factor theories; and thermoacoustical parameters.