Ranjan Dey

Estimation of molecular radius of liquids and liquid mixtures from sound velocity

Abstract Various acoustic methods have been utilized to compute the molecular radius of pure liquids and liquid mixtures at varying conditions. The values thus obtained have been compared against the values obtained from a non-acoustic method, which uses refractive index data. These results have been utilized to study the relative merits of these various relations. An attempt to correlate the molecular radii of the liquids and liquid mixtures with other related properties of the liquid system has also been made. The applicability of an acoustic method like Schaaffs’ method for the computation of the molecular radius in liquid mixtures has also been authenticated.

Speed of sound, viscosity and refractive index of multicomponent systems: theoretical predictions from the properties of pure components

Abstract Theoretical prediction of speed of sound, viscosity and refractive index of three ternary systems: toluene + n-heptane + n-hexane (I), cyclohexane + n-heptane + n-hexane(II) and n-hexane + n-heptane + n-decane (III) have been made on the basis of empirical, semi-empirical and statistical mechanical theories using the properties of pure components. Theoretical results are compared with the experimentally measured values at 298.15 K.

ULTRASONIC VELOCITY OF BINARY SYSTEMS AT ELEVATED PRESSURES

Various empirical theories of ultrasonic velocity have been applied to three binary liquid mixtures, under pressures up to 200 MPa and their validity have been tested. A pressure dependent study of ultrasonic velocities has been made at 303.15 K. The agreement between theory and experiment is found to be quite satisfactory.

Thermoacoustical approach to the intermolecular free-length of liquid mixtures

The intermolecular free-length is evaluated by making use of thermoacoustical parameters followed by a comparative study. To achieve this objective, thermoacoustical parameters of four ternary and two quaternary liquid mixtures have been computed. These parameters have been utilized to calculate the available volume (Va), which in turn has been used to compute intermolecular free-length (Lf) for the systems under investigation. The computed values of Lf have then been compared with the values estimated from well-established thermodynamic and ultrasonic methods. To the best of our knowledge, this investigation is a pioneering attempt in evaluation of intermolecular free-length involving multicomponent liquid mixtures by making use of thermoacoustical parameters.

Prediction of Heat of Mixing from Internal Pressure Data

Abstract Excess enthalpies (HE m) and excess heat capacities (CE p) of three binary liquid mixtures comprising dimethylformamide, acetonitrile and benzene have been evaluated from internal pressure data obtained from three different approaches. The results obtained have been compared with the experimental HE m and CE p values determined by Miyanaga et al. [1]. HE m values evaluated through density, viscosity and ultrasonic velocity data [2] show anomalous behaviour. A critical review has been given.

A comparative study of non-linearity parameter for binary liquid mixtures

The present investigation comprises of theoretical evaluation of acoustic non-linearity parameter,B/A for equimolar binary mixtures, viz. chlorobenzene or 1-chloronaphthalene with a series of normal alkanes (n-Cn,n = 6, 8, 10, 12, 14, 16), and with a series of highly branched alkanes (br-Cn,n = 6, 8, 12, 16), viz. 2,2-dimethylbutane (br-C6), 2,2,4-trimethylpentane (br-C8), 2,2,4,6,6-pentamethylheptane (br-C12) and 2,2,4,4,6,8,8-heptamethylnonane (br-C16). Tong and Dong method, thermoacoustical method, Hartmann relation and Ballou relation have been employed to evaluateB/A. A comparative study ofB/A values obtained from the aforementioned methods has been made. The results are discussed on the basis of structural orientations of normal and branched alkanes.

Thermodynamic Properties of Multicomponent Liquid Mixtures

Considering a ternary liquid mixture to be made up of three binary mixtures, by means of cell model using Sutherland type potential function for pair interaction between molecules, a statistical theory for binary liquid mixtures has been extended for ternary systems. In the light of above extension, excess volume ( V E ), excess energy ( E E ) and excess entropy ( TS E ) have been computed for three binary (benzene + cyclohexane, benzene + chlorobenzene and cyclohexane + chlorobenzene) and the resultant ternary system (benzene + cyclohexane + chlorobenzene) at 298.15 K. All the above mentioned excess properties have been computed from the data of ultrasonic velocity and density only.

Host–guest interaction between corannulene and γ-cyclodextrin: mass spectrometric evidence of a 1 : 1 inclusion complex formation

The toroidal cavity of γ-cyclodextrin is shown to interact with a bowl-shaped polycyclic aromatic hydrocarbon, corannulene, through host–guest interactions.

Novel approach for prediction of ultrasonic velocity in quaternary liquid mixtures

A modified Flory theory along with the Auerbach and Altenberg relations has been employed for the computation of ultrasonic velocity of three quaternary liquid mixtures and a comparative study of all the three relations has then been carried out.

A modified Frenkel approach for viscometric prediction of binary and multicomponent liquid mixtures

Viscosity measurements serve as a very vital and versatile tool for flow measurements and to study intermolecular interactions in liquid mixtures especially in the field of petrochemical and reservoir engineering. The need for development of newer models for theoretical evaluation of viscosity is a matter of considerable significance and various theories have been proposed by several workers over the years. Present investigation is an attempt to modify the well established Frenkel relation for prediction of viscosity. The modified relation has been applied to 100 binary, 14 ternary and 2 quaternary systems over a wide range of temperature. The obtained results have been compared with few predictive and correlative approaches in literature alongwith the original Frenkel relation by taking absolute average percentage deviation (AAPD) as the criterion. The model testing results clearly indicate the superior predictive capability as compared to the original relation. The improvements in AAPD values are seen to be as high as 80.86 times (8085.7%) for binary and 5.85 times (585%) in case of ternary system.