Absorption and dispersion of the field induced dielectric increment in caprolactam–cyclohexane solutions

Abstract

The nonlinear dielectric effect in solutions of ε-caprolactam in cyclohexane is studied by a new differential technique over the frequency range of 2 to 100 MHz. The frequency dependent real and imaginary parts of the field induced permittivity increment are obtained. Cole–Cole plots show a concentration dependent dielectric relaxation, to which a single Debye term is fitted. The relation of relaxation times with concentration is not consistent with a simple dimerization mechanism. Static permittivity measurements indicate the presence of polar associates. An expression is derived including those contributions to the observed nonlinear effect, which are frequency independent within the range studied. Calibration measurements on diethyl ether–cyclohexane solutions are reported and the effect measured in pure cyclohexane is discussed.