Thermoelectric Performances Of Polyaniline/Silver Nanowires/Carbon Nanotubes Composites

Polyaniline(PANI)was one of the most widely studied thermoelectric polymers due to its widely tunable electrical conductivity,environmental stability and its easy to synthesis among those conductive polymers.Silver nanowires(AgNWs)had attracted wide attention due to unique one-dimensional nanostructure,its superior photoelectric properties and transparent flexibility among functional materials field.Carbon nanotubes(CNTs),as one-dimension carbon nanostructure,because of excellent mechanical and electrical properties,good thermal stability and chemical stability,had been considered to be the important application prospects in thermoelectric material.In this paper,we studied PANI as the research object,AgNWs or CNTs as an enhancosome,in order to study the thermoelectric performance of PANI based composites.(1)PANI/AgNWs composites were used to different preparation methods through in-situ polymerization and physical blending.The microstructure and thermoelectric properties of the nanocomposites were investigated by the different content of AgNWs.With the increase of AgNWs,the results showed that the conductivity of PANI increased,but the Seebeck coefficient decreased.The maximum value of power factor was 0.585?W/mK~2 by physical blending of PANI/AgNWs,higher than the power factor of the in-situ polymerization.(2)Polyaniline:Polystyrenesulfonate/silvernanowiresnanocomposites(PANI:PSS/AgNWs)had been fabricated via incorporating AgNWs into PANI:PSS with simple physical mixing.The water dispersion,microstructure and thermoelectric properties of nanocomposites were investigated.The addition of PSS enhanced the water dispersibility of Polyaniline and effectively improved the Seebeck coefficient of the nanocomposites,so it played an important role in enhancing the thermoelectric performanc of nanocomposites.The maximum power factor of 0.85?W/mK~2 was achieved with the addition of 9.0 wt.%AgNWs at a PANI:PSS mass ratio of 1:5,which was 6 times,28 times higher than that of PANI:PSS and PANI.Therefore,the incorporation of PSS provided an effective way to improve the thermoelectric properties of conductive PANI:PSS/AgNWs polymer composites.(3)The PANI:PSS/AgNWs/a-MWCNT composites were prepared via incorporating a-MWCNT into PANI:PSS/AgNWs by simple physical blending.The microstructure and thermoelectric properties of the composites were investigated.The results showed that the conductivity and Seebeck coefficient of the composites were increased with incorporation of a-MWCNT,which should be attributed to?-?bond interaction between a-MWCNT and PANI molecules.The maximum electrical conductivity of 57.3 S/m was achieved with the addition of 3.22 wt.%a-MWCNT,which was 3.3 times more than the conductivity of PANI:PSS/AgNWs.Finally,the maximum value of power factor was 2.6?W/mK~2,which was an order of magnitude more than PANI:PSS/AgNWs.The maximum Seebeck coefficient of 233?V/K was achieved with the addition of 1.64 wt.%a-MWCNT.