Showing papers by "Sylwester J. Rzoska published in 1992"

Critical properties in the vicinity of the critical consolute point for the 4-methoxybenzylidene-4′-butylaniline-isooctane solution

Abstract: Results are presented of measurements of the non-linear dielectric effect on approaching the critical consolute point in a solution composed of a liquid crystal (MBBA) and a non-mesogenic component (isooctane). The coordinates of the critical point are T c ≈ 2°C and x c ≈ 0.77 mole fraction of isooctane. The exponent ψ describing the critical effect of the non-linear dielectric effect is the same as that for a binary solution of ordinary liquids (ψ ≈ 0.37, i.e. it is non-classical). It should be stressed that it is the smallest critical effect which has been ever analysed by means of this method. For small concentrations of isooctane the exponent ψ ≈ 1, i.e. the behaviour is classical. In the system studied the coexistence curve with the critical consolute point appears for concentrations of isooctane greater than 0.45. Its form is also characteristic of a solution of two ordinary, non-mesogenic, liquids (i.e. β = 0.34 ± 0.01).