Water in keratin: Study of the depolarization thermal current peak II

The depolarization thermal current method is applied to the study of the polarization phenomena in the keratin‐water system. Three depolarization thermal current peaks have been evidenced in hair keratin. This paper deals with the detailed study of peak II. For the first time, the mechanism responsible for this peak is ascribed to molecular reorientation. The effect of water upon the characteristics of peak II is also described, and an activation energy of 8.4 kcal/mol is computed. These results, in connection with other studies, lead us to interpret peak II as due to the reorientation in the bound or intermediate water molecules. The effect of copper confirms that the carboxyl groups are hydration sites.