Fluid Phase Equilibria, Vol.167, No.2, 207-221, 2000
Volumetric manifestation of van der Waals interactions between cholesterol and organic solvents of linear structure
The densities of solution of cholesterol in several selected n-alkanes, alkan-1-ols and tertiary amines have been measured at 298.15 K. The values of standard partial molar volume of cholesterol have been calculated and the effect of solute-solvent and solvent-solvent interactions on the partial molar volume of cholesterol have been discussed. The increase in the alkyl chain length (R-i) of solvents such as alkanes and amines enhances the dispersion solvent-solvent interactions (per -CH2-) and weakens the contribution of dispersion forces in the cholesterol-solvent interactions. Both these effects bring about an increase in the partial molar volume of cholesterol with increasing the alkyl chain length of solvent molecules. In alcohols, the cholesterol-solvent dispersion interactions increase with R-i. This effect may be accounted for by the self-association of the solvent. In consequence, there is no distinct dependence of partial molar volume of cholesterol on the alkyl chain length of alcohol.
Keywords:density;partial molar volume;cholesterol;alkanes;alkan-1-ols;tertiary amines;van der Waals interactions;dispersion forces;solvation