On the critical behavior of linear and nonlinear dielectric permittivity on approaching the critical consolute point

Results are presented of the dielectric permittivity /spl epsi/ and nonlinear dielectric effects (NDE) in binary mixtures on approaching the critical consolute point (CCP), focusing first on Piekara's findings [Phys. Rev. Vol.42, pp. 445-447, 1932, and C. R. Acad. Sci. Paris Vol. 203, pp. 1058-1059, 1936]. The presented results cover changes in temperature and pressure. For NDE particular attention is given to complex liquid features of critical mixtures appearing in /spl epsi/ and NDE tests. The latter are presented for the stationary and dynamic (time-resolved NDE) behavior. New results for NDE in nitrobenzene, hexane mixture with the lowest measurement frequency ever applied and in benzonitrile-isooctane mixture for dielectric permittivity are also included. For the latter, the first test of the relation: d/spl epsi//dT /spl alpha/ (T - T/sub C/) /sup -/spl alpha// is shown.