Kalidoss—Jacobson Free Length Theory Applied to Binary Liquid Mixtures of CCI4+Toluene/Aniline/oCresol m-cresol p-Cresol

Abstract

Ultrasonic velocities and intermolecular free lengths in binary liquid mixtures of CC4 with toluene, aniline, o-cresol, m-cresol and p-cresol have been calculated theoretically, at different compositions and at temperature 298 K, based on Free Length Theory as revised recently by Kalidoss. It is observed that there is a close agreement of calculated velocities with experimental ones. The shape and thermostatic state picture built up in this formulation could be considered as a good representation of molecular state.     

Solubility of Trans-Stilbene in Binary Alkane + 1-Propanol Solvent Mixtures at 298.2 K

Abstract

Experimental solubilities are reported for trans-stilbene dissolved in six binary alkane + 1-propanol solvent mixtures at 25°C. the alkane cosolvents studied were hexane, heptane, octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister and Modified Wilson equations. for the six system studied, the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister equation provided the better mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being approximately 0.4%. Slightly larger deviations were noted in the case of the Modified Wilson equation.     

Solubility of Trans-Stilbene in Binary Alkane + 1-Butanol Solvent Mixtures at 298.2 K

Abstract

Experimental solubilities are reported for trans-stilbene dissolved in six binary alkane + 1-butanol solvent mixtures at 25°C. The alkane cosoivents studied were hexane, heptane, octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister and Modified Wilson equations. For the six systems studied, the Combined NIBS/Redlich-Kister equation was found to provide the better mathematical representation of the experimental data, with overall average absolute deviations between measured and calculated values being approximately ±0.6%. Slightly larger deviations were noted in the case of the Modified Wilson equation.     

Surface tension and density of binary mixtures of monoalcohols,water and acetonitrile: equation of correlation of the surface tension

Measurements of the surface tension (σ) and density (ρ) of binary mixtures of monoalcohols, water and acetonitrile at 298.15 K and at atmospheric pressure, as a function of mole fraction (x) have been made. The experimental values of the deviation of surface tension and the excess of molar volume (Δσ, V ^E) have been correlated by the Redlich–Kister equation. An empirical correlation equation is presented for the study of the surface tension of these mixtures, and comparisons are made of the experimental values of surface tension versus those obtained with the correlation equation and with other models of correlation. Finally, with the purpose of corroborating the validity of the correlation equation, the latter is applied to other reference binary mixtures.     

Analysis of Excess Molar Volumes of the Ternary Systems Containing a Propyl Alkanoate and Two Alkanes with Some Predictive Methods

Abstract

Excess molar volumes at 298.15 K of the ternary mixtures (propyl ethanoate + n-heptane + n-decane), (propyl propanoate + n-heptane + n-decane) and (propyl butanoate + n-heptane + n-decane) were determined using a DMA 60/602 Anton Paar densimeter. All the experimental values were compared with the results obtained with empirical expressions for estimating ternary properties from binary data and with the Nitta-Chao group-contribution model. For these ternary mixtures the same behaviour that had been observed in ester + n-alkane binary systems was found: excess volumes decrease when the ester length increases.     

Surface Tension of the Liquid Hg-In Alloys

Abstract

The measurements of the surface tension of the liquid Hg-In alloys were made by means of a maximum drop pressure method. The surface tension increases monotonously with increasing the In concentration. It is thermodynamically shown that the composition of the Hg atoms adsorbed on the surface is larger than that in the bulk. Experimental results are compared with calculated results due to various model theories; in particular the hard sphere model with a density-dependent cohesive potential is found to be in qualitative agreement with experimental results of both surface tensions and its temperature coefficients.     

Excess Volume of Ternary Water + Diacetone Alcohol + 2-Propanol as a Function of Pressure,Temperature and Composition

Abstract

The excess volume V^E of the ternary water + diacetone alcohol (or DAA) + 2-propanol and of the three binaries water + DAA, water + 2-propanol and DAA + 2-propanol was evaluated from experimental density data (2772 values) as a function of the pressure P (between 0.1 MPa and 65 MPa), the temperature T (303.15K, 323.15K and 343.15K) and the composition. Various representative models are discussed. It is possible to account for the values of the density with an average absolute deviation of about 0.06% in the experimental P-T domain.     

Heuristic treatments of tricritical behaviour as observed in 4He–3He mixtures and in polymeric assemblies

Tricritical behaviour in three dimensions is accessible to experiment in, for example, ⁴He–³He mixtures and some polymeric assemblies. Here, by largely heuristic arguments, which appeal however to some specific model Hamiltonians, we indicate how one can understand the gist of the experimental results near the tricritical point in the systems cited above. We point out that the spin fluctuations at the tricritical point are much weaker than those at the critical point, which leads to the conclusion that the tricritical behaviours can be described well by the mean-field exponents with logarithmic corrections, at d = 3.     

Speed of sound,isentropic compressibilities and viscosities of ternary non-electrolyte solutions at 303.15 K

Measurements of ultrasonic speeds, isentropic compressibilities and viscosities were carried out for six ternary mixtures namely dimethylsulphoxide (1) + 1,2-dichlorobenzene (2) + 1-alkanols (3) at 303.15 K. The 1-alkanols include 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol. The ultrasonic speeds of these ternary mixtures were also evaluated on the basis of Jacobson's free length theory and Schaaff's collision factor theory. From the viscosity data, deviations in viscosity and interaction parameters for various models were also calculated. An attempt has also been made to explain the nature of intermolecular interactions in the light of deviation in isentropic compressibilities and interaction parameter.     

Phase behaviour of star-shaped binary mixtures of triphenylbenzenes,triphenylboroxines and triphenyltriazines

ABSTRACT

Star-shaped nonaalkoxy-1,3,5-triphenyltriazines were prepared and their mesomorphism was investigated by differential scanning calorimetry (DSC), polarised optical microscopy (POM) and X-ray diffraction (WAXS and SAXS). Compounds with chain lengths C₉ – C₁₂ displayed enantiotropic hexagonal columnar mesophases over a wide range of temperature. Their similarity in molecular size and mesomorphism prompted us to study their binary mixtures with previously reported planar 1,3,5-triphenylboroxines and propeller-shaped 1,3,5-triphenylbenzenes. All three compounds are fully miscible in their hexagonal columnar mesophases, but mixtures of planar with propeller-shaped compounds generated columnar stacks that contain only one type of molecule to avoid their shape incompatibility. However, the two types of columnar stacks were fully miscible which circumvented macroscopic phase separation.