Analysis of the pure SWCNTs and SWCNT dispersions

A different batch of SWCNTs, namely Carbolex SWCNTs, were used in the preparation of SWCNT/PS/PEDOT PSS composites.Carbolex SWCNTs are produced by arc-discharge technology. This technique is used to produce SWCNTs on a large scale but with the disadvantage 

The exfoliation of Carbolex SWCNTs was performed with both SDS and PEDOT PSS. The UV-Vis absorption spectra revealed a profile from which it was apparent that the final absorbance level reached was similar for dispersions prepared with SDS and PEDOT PSS, unlike that previously seen for HiPCO SWCNTs.This suggests that the electronic interaction between the Carbolex SWCNTs and PEDOT PSS is different from that observed for HiPCO SWNCTs. Examining their respective absorption spectra, as well as using Raman spectroscopy one can examine the difference in electronic structure of the SWCNTs. 

SWCNTs. This implies that the SWCNT surface chemistry (degree of graphitization] could differ greatly for the two batches, although this counters the observation of the TGA results. It should, however, not be forgotten that a featureless absorption spectra could also be linked to a lesser degree of individualization of the SWCNTs. 

To further probe the SWCNTs purity, their intrinsic conductivities were measured by preparing buckypapers from the respective dispersions. Conductivities of buckypapers prepared from HiPCO and Carbolex SWCNTs were approximately 1 x 10 and 1 x 10 S m, respectively. The significant difference in intrinsic conductivities indicates that there is certainly a difference in the electronic properties of the SWCNTs. The lower conductivity of the Carbolex SWCNTs could be attributed to more wall defects, a larger fraction of semi-conducting SWCNTs or a carbonaceous coating on the SWCNT wall. To determine the main cause of these lower conductivities would require further investigation. For the application intended here, this difference is of utmost importance. One further prerequisite is that the aspect ratio of the two SWCNT batches is not vastly different. 

The ultimate conductivity of the SWCNT/PEDOT PSS/PS composites is similar to that of the control blends (PEDOT PSS/ PS). It is important to note that the ultimate conductivity of HiPCO SWCNT/PS/PEDOT PSS composites is less than one order of magnitude higher than the corresponding conductivity of poor quality Carbolex SWCNT/PS/PEDOT PSS composites. The difference between HiPCO SWCNT/PS and Carbolex SWCNT/PS composites without the presence of PEDOT PSS, however, is approximately two 

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