Dielectric relaxation in hydrated elastin

Abstract

Abstract The dielectric properties of water absorbed in elastin are measured for different water, NaCl and HCl contents over the frequency range 102–105 Hz from 20 to—60°C. For all samples, both the dielectric constant and the loss factor decrease monotonically with increasing frequency or decreasing temperature. The absence of a maximum in the loss curves is indicative of an extremely broad spectrum of relaxation times. By shifting the data along the log frequency axis, all the curves obtained for the dielectric constant and the loss factor at different temperatures are represented on master curves at an arbitrarily chosen temperature. The results are explained on the basis that hydrogen-bonded water clusters with a wide size distribution exist in contact with elastin and that their diffusion is the rate determining step for dipolar orientation. These water molecules are nonfreezable and quite mobile at low temperatures until a glassy state results at approximately 130°K.