Pressure and temperature studies of dielectric permittivity in the homogeneous phase of nitrobenzene-dodecane binary mixture

Results of isothermal high-pressure (up to 120 MPa) and isobaric (P = 0.1 a nd 51 MPa) temperature studies of dielectric permittivity in nitrobenzene-d odecane binary solution are presented. The dependencies of epsilon(p) and e psilon(T) obtained can be well portrayed by isomorphic relations with the s ame value of the critical exponent phi = 1 - alpha approximate to 0.88. The influence of correction-to-scaling terms for the temperature and pressure paths is shown. It has been found that the strength of the pretransitional anomaly of the isothermal pressure path is definitely larger than that of t he isobaric temperature path. The influence of the Maxwell-Wagner effect wa s found to be insignificant in the isothermal pressure studies even for a f requency of 100 Hz. Data were completed by the results of low-frequency (25 0 kHz) measurements of the shift of dielectric permittivity due to applicat ion of a strong electric field (the non-linear dielectric effect). (C) 1999 Elsevier Science B.V. All rights reserved.