Coupling of the electrical conductivity to the structural relaxation, absence of physical aging on the time scale of the Debye process, and number of correlated molecules in the supercooled monohydroxy alcohol 2-ethylhexanol

Abstract

Using dielectric experiments the structural, the Debye-like, and the conductivity relaxation times of 2-ethyl-1-hexanol are measured in a wide temperature range. It is found that the electrical transport scales with the temperature dependence of the structural relaxation but that it is decoupled from that of the Debye-like response. Temperature-jump experiments were carried out, and signs of a physical aging on the time scale of the Debye-like response could not be detected. The minimum number of correlated molecules contributing to the structural and to the Debye-like responses was estimated on the basis of the temperature derivative of the susceptibility as expressed in terms of the fragility index and of the spectral line shape parameters.