| Thermoelectric?TE?material is a kind of“green”functional material,which can directly covert thermal energy to electrical energy and vice versa.Conducting polymer TE materials have many advantages,such as low thermal conductivity,abundant raw materials,easy processing and fabrication for flexible TE mateirals,etc.,when compared with traditional inorganic materials.Among them,polypyrrole?PPy?has become a research hotspot and has a great potential for the application in the TE research area.However,the TE properties of PPy and PPy-based nanocomposites are still much lower than that of inorganic TE materials,therefore,it is of great significance to carry out a more in-depth study for PPy and PPy-based nanocomposites.Herein,this thesis mainly focused on the following aspects:PPy nanosturcures with different morphologies?nanoparticles,nanotubes,nanowires?were prepared by a chemical oxidation or"soft template"method,respectively.The power factor of the prepared PPy particles,PPy nanotubes,and PPy nanowires at 300 K were 0.0037?W/mK2,0.068?W/mK2 and 0.31?W/mK2,respectively.Poly?3,4-ethylenedioxythiophene?:poly?styrenesulfonate??PEDOT:PSS?/PPy particle/paper,and PEDOT:PSS/PPy particle/cotton fabric flexible composite films were successfully prepared by an in-situ polymerization combined post-treatment procedure.PEDOT:PSS/PPy nanotube/paper flexible composite film was successfully prepared by an soft template-in-situ polymerization combined post-treatment procedure.The results show that the electrical conductivity and the Seebeck coefficient of the above-mentioned composite films increased as the temperature increasing,and the positive values of the Seebeck coefficients indicated that all the prepared composite films were P-type thermoelectric materials.At 300 K,the ZT values??of the PEDOT:PSS/PPy particle/paper,PEDOT:PSS/PPy particle/cotton fabric,and PEDOT:PSS/PPy nanotube/paper flexible composite films are 1.85×10-5,2.9×10-55 and4.13×10-6,respectively,which is much higher that that of PPy particle/paper(4.73×10-7),PPy particles/cotton fabric(1.46×10-6),and PPy nanotube/paper(3.2×10-7)flexible composite films.The as-prepared composite films have many advantages,such as stabe TE properties,low density and good flexiblilty.PPy nanowire/graphene?GR?and PPy nanotube/GR composites were prepared by an soft template-in-situ polymerization method,respectively.The electrical conductivities and Seebeck coefficients of the above-mentioned nanocomposites were increased as the temperature increasing from 300 K to 380 K.The electrical conductivity of PPy nanowire/GR and PPy nanotube/GR nanocomposites was higher than that of pure PPy nanowires and PPy nanotubes,respectively,and their Seebeck coefficients also increased as the GR content increasing.A maximum power factor of 1.01?W/mK2?3.26 times higher than that of pure PPy nanowires?and 0.18?W/mK2?2.65 times higher than that of pure PPy nanotubes?was obtained at 380 K for the PPy nanowire/GR and PPy nanotube/GR nanocomposites with20wt%GR,respectively. |
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