Influence of intermolecular interactions on the sign of dTC/dp in critical solutions Original Research Article

Results of studies on variations of the critical temperature (TC) due to the action of high hydrostatic pressure (p) are presented. Studies were conducted in three series of critical solutions composed of a dipole component (nitrobenzene, o-nitroluene, 1-nitropropane) and a non-dipole solvent (n-alkanes). For solutions containing nitrobenzene and o-nitrotoluene the sign and value of dTC/dp depend on the length of the molecule of n-alkane. Additional studies on dipole-dipole interactions between molecules of the dipole components by means of the nonlinear dielectric effect indicate their important influence on dTC/dp.