PEDOT: PSS/CNT

In 2008, Kim et al. prepared a series of segregated-network PEDOT PSS/ CNT composites by mixing CNTs with a poly(vinyl acetate) (PVAc) homopolymer emulsion, as shown in Figure 6.14 [24]. They found that the CNTs form a three-dimensional network along the surfaces of the spherical emulsion particles. They added conductive polymer particle PEDOTiPSS into the composites, which are decorated on the surface of electrically... 

They further prepared PEDOT PSS/CNT composites with higher CNTs content (higher than 35 wt.%) by direct solution mixing [26], whose microstructures are different from those of segregated-network polymer composites. The nanotubes were pulled out from the composite rather than being fractured or embedded in the matrix, due to the high CNTs content, as shown in Figure 6.16. 

PEDOT PSS/CNT is another important type of CP-based composite TE materials. In 2008, Kim et al. foxmd that the segregated-network polymer/ CNT composites dramatically increased with rising CNT concentration in the composite, while their thermal conductivity and Seebeck coefficient remained relatively insensitive to the filler concentration (Figure 6.31) [24]. 

Recently the idea of Ago et al. to replace the ITO electrode by a CNT based electrode was pursued by several groups again. However, this time SWNTs were used [330-333]. The motivation for this step is generally found in the benefit of replacing an expensive vacuum step in the fabrication of polymer solar cells [330] with roll-to-roll production of supporting nanotube electrodes (Fig. 67) [331], which will aid in the removal of ITO and PEDOT PSS related problems [332] while facilitating applications of flexible devices on plastic substrates [333]. 

Figure 6.32 Electrical conductivity and thermopower of the composites with XM-CNT (20 wt.%) or SWCNT (20 or 35 wt.%) and 1 1 or 1 2 ratio between CNT and PEDOT PSS at room temperature.

In 2012, G. H. Kim et al. prepared Gp-filled PEDOT PSS composite films via solution spin coating method [3]. XPS and Raman analyses identified that strong tt-tt interactions existed between Gp and PEDOT PSS, which facilitated the dispersion of Gp in the polymer matrix and reduced the carrier hopping barrier. The uniformly distributed Gp increased the interfacial area by 2-10 times as compared with CNT based composite on the same weight percentage. Moreover, well-stacked multilayer structure... 

It is difficult, If not impossible, to ascertain the extent to which the PEDOT PSS has covered the CNTs themselves. 

A control series of films, prepared by mixing the PS latex and PEDOT PSS, was investigated to determine the critical PEDOT PSS loading required to prepare a conductive film without the presence of CNTs. An insulator-conductor transition around 2.2 wt% is observed for PS/PEDOT PSS blends. 

PNMA, poly(N-methylaniline) PANI, poly(aniline) PEDOT, poly(3,4-ethylenedioxythiphene PSS, poly(styrene-sulfonate), PPy, poly(pyrrole) PEO, poly(ethylene oxide) DBSA, dodecylbenzene sulfonic acid CSA, camphor sulfonic acid PTSA, poly(o-toluene sulfonic acid) PFOA, perfluoro-octanolc acid TSA, toluene sulfonic acid CNF, carbon nanofiber SWCNT, single-walled carbon nanotube NP, nanoparticle MWCNT, multiwalled carbon nanotube PTh, poly(thlphene) CNT, carbon nanotube POA, poly(o-anisidine) SPANI, poly(anilinesulfonlcacld) PB, Prussian Blue DAB, 1,2-diamino benzene POEA, poly(o-ethoxyanlllne) PMMA, poly(methyl methacrylate). 

---