fig4

Figure 4. (A) Synthesis mechanism of PANI, (B) FESEM image of HCl (1.0 M) doped PANI powder and (C) The temperature dependence of the Seebeck coefficient of various HCl-doped PANI. (A-C) Reproduced with permission^[67]. Copyright 2010, Elsevier; (D) Schematic of the layer‐by‐layer deposition process; (E) The structure of thermoelectric film components used; (F) Images of aqueous PANI solution, and graphene and DWCNT stabilized by PEDOT:PSS, in water; (D-F) Reproduced with permission^[70]. Copyright 2016, WILEY‐VCH; (G) Schematic illustration showing the preparation process for the PPy nanostructures by chemical oxidation polymerization; (H) Thermoelectric performance of electrical conductivity, Seebeck coefficient and power factor for PPy prepared with different oxidants; (I) Thermoelectric performance of electrical conductivity, Seebeck coefficient and power factor for PPy nanowires prepared at different APS concentrations; (J) Thermoelectric performance of electrical conductivity, Seebeck coefficient and power factor for the PPy samples prepared in various reaction media; (G-J) Reproduced with permission^[71]. Copyright 2017, Royal Society of Chemistry; (K) Schematic presentation of the PEDOT benzoid structure, the ordered quinoid structure in bulk and nanostructured PEDOT samples and Thermoelectric performance of bulk PEDOT and PEDOT nanostructures; FESEM images of (L) bulk PEDOT power and PEDOT nanostructures of (M) globular nanoparticles, (N) nanorods or ellipsoidal nanoparticles, (O) nanotubes and (P) nanofibers; (K-P) Reproduced with permission^[77]. Copyright 2015, Royal Society of Chemistry. PANI: Polyaniline; PEDOT: poly(3,4-ethylenedioxythiophene); PSS: polystyrene sulfonate; PPy: polypyrrole; APS: ammonium persulfate; FESEM: field emission scanning electron microscope; DWCNT: double-walled carbon nanotube; DWNT: double-walled nanotube.