The unusual electrical response in polyaniline-threonine composites

Polymer-amino acid composites are a new class of polymer materials with unusual electrical property. Novel polyaniline-threonine composites combining the synthesized polyaniline and proteinogenic amino acid threonine have been prepared. The samples were characterized by Fourier-transform infrared spectra, UV-vis absorption spectra and atomic force microscopy. The unusual electrical response was found from the d.c. conductivity measurement. The carboxyl group of the amino acid threonine played an important role in the electrical conductivity. Analysis of d.c. conductivity data revealed that in the temperature range of 300 K-200 K, the d.c. conductivity was governed by Mott's 3-dimensional variable range hopping