Electric properties of liquid crystalline polypeptide thin films

Linear poly(/spl gamma/-alkyl substituted-/spl alpha/, L-glutamate)s exhibit interesting thermal and morphological properties in the bulk state. We report on the electrical and thermal characterization of poly(/spl alpha/-alkyl substituted-/spl alpha/, L-glutamate)s using thermally stimulated polarization and thermally stimulated discharge current measurements as well as differential scanning calorimetry. The TSPC shows big variations at the onset of the melting during the heating of the sample and at the onset of solidification during cooling. In this region the activation energy can be very high. Values between 1.16 eV and 4.39 eV were obtained. For low fields the transition is not so well observed. In TSPC measurements some minimums appear at field reversal. The TSDC peak is very broad and moves to higher temperature as the polarization field or polarization temperature increases. The TSDC changes sign in some conditions, but this is not an intrinsic sample property.