The dielectric relaxation of water between 0°C and 35°C

Abstract

Precise complex permittivity data from the authors' lab. for pure water at temps. 0.2 ≤ .vtheta./°C ≤ 35 are combined with literature results to cover the frequency range 0.2 ≤ ν/GHz ≤ 410. A description of the ε(ν) spectra requires the superposition of two Debye processes. Nonetheless, relaxation times and dispersion amplitudes discourage the discussion of the water structure in terms of a two-state model. The interpretation of the fast process with the relaxation time τ2 requires addnl. information, whereas it is possible to relate the relaxation time τ1 of the dominating slow process to the prodn. rate of mobile water mols. From the corresponding Eyring free energy, ΔG≠, hydrogen-bond probabilities are deduced, which are in good agreement with data from other methods.