Electrical conductivity of carbon nanotubes and polystyrene composites

• Published in: Physica status solidi. C Vol. 5; no. 9; pp. 3172 - 3174
• Main Authors: Kažukauskas, V., Kalendra, V., Bumby, C. W., Ludbrook, B. M., Kaiser, A. B.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.07.2008; WILEY‐VCH Verlag
• Subjects: 61.46.+w; 72.80.Tm; 73.23.−b; 81.07.De; 81.07.Pr; 81.40.Rs
• ISSN: 1862-6351; 1610-1634; 1610-1642
• DOI: 10.1002/pssc.200779193

We report investigation of electrical conductivity of high resistivity polystyrene/carbon nanotube composites. The films consisted of a thiol‐bonded network of wrapped MWNTs within a polystyrene matrix with mass ratios ranging from 0% to 1%. The electrical conductivity and its thermal activation energy were systematically depending on the CNT doping level. A number of phenomena could be explained by the presence of CNT ‘islands’ in the polystyrene matrix at doping levels below the percolation threshold. At higher levels of CNTs an interconnected conducting network is formed. The results appear consistent with fluctuation‐assisted tunnelling through barriers between conducting carbon nanotubes for medium and large voltages. However, at low voltages there is a sharper decrease in conductance as voltage decreases that could arise from Coulomb blockade effects or other small barriers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)