The influence of temperature on elastin\u2013water dielectric properties

Abstract

The main purpose of this article is the in vitro study of elastin from the bovine neck ligament using dielectric spectroscopy in the alpha electric field dispersion region in the temperature range from 22 to 200 °C. The temperature dependence of the relative permittivity of wet elastin indicates a maximum of about 50 °C due to the thermal decomposition of loosely bound water, as well as a rapid decrease in this parameter above 185 °C. For a dry elastin, the change in relative permittivity with temperature represents only one peak of high temperature around 185 °C, corresponding to the glass transition temperature (Tg). Below Tg, the activation energy of conductivity for wet and dry elastin at 50 kHz, responsible for the breaking of hydrogen bonds between bound water molecules and hydrophilic polar groups of the main elastin chains, is 27 and 11 kJ mol−1, respectively, and above Tg, corresponding activation energy values associated with relaxation of the main chain increase to 72 and 34 kJ mol−1. In this article, dielectric processes related to the glass transition temperature, especially in the case of dry elastin, can play an important role in the use of solid-state elastin as a biomaterial for various tissue engineering applications.