Preparation and thermoelectric properties of PANI matrix graphene composite material

Abstract

Enormous amounts of unused waste heat have created a strong demand for high-efficient heat-to-electric generators, so thermoelectric (TE) material (i.e. a kind of semiconductor which can generate electricity from a temperature difference) has become increasingly important. However, the inorganic TE materials are expensive, scarce reserves in the earth crust, poisonous and hard to be processed, so the research and development of organic TE materials are very urgent. The polyaniline (PANI, i.e. one of the conducting polymer) and PANI matrix graphene composite material were prepared. The chemical structure, microstructure and properties were investigated by Fourier transformer infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and TE properties measurement system. Results showed that the distribution of the molecule chains in PANI were irregular, however, graphene worked as an interconnected network in the composite materials when 20 wt% graphene was added. Power factor, electrical and thermal conductivities of the composite material increased greatly while ZT (i.e. the figure of merit) of which was two times of PANI. The addition of graphene was an effective method to increase the TE properties of PANI.