Modeling Carbon Nanotube Electrical Properties in CNT/Polymer Composites

In this work it is demonstrated that the capacitance between two cylinders increases with the rotation angle and it has a fundamental influence on the composite dielectric constant. The dielectric constant is lower for nematic materials than for isotropic ones and this can be attributed to the effect of the filler alignment in the capacitance. The effect of aspect ratio in the conductivity is also studied in this work. Finally, based on previous work and by comparing to results from the literature it is found that the electrical conductivity in this type of composites is due to hopping between nearest fillers resulting in a weak disorder regime that is similar to the single junction expression.

This work is funded by the Foundation for Science and Technology, Lisbon,through the 3 Quadro Comunitário de Apoio, POCTI and FEDER funds through the ‘‘Programa Operacional Factores de Competitividade—COMPETE’’, project references PEst-C/CTM/LA0025/2011, NANO/NMed-SD/0156/2007, PTDC/CTM/69316/2006, PTDC-EME-PME-108859-2008, and PTDC/CTM-NAN/112574/2009 and grant SFRH/BD/60623/2009 (JS). The authors also thank support from the COST action MP0902 ‘‘Composites of Inorganic Nanotubes and Polymers (COINAPO)’’.