Effects of chlorinated aromatic solvents on the dispersion of HiPco SWNTs

A systematic study of the effect of chlorinated aromatic solvents such as monochlorobenzene (MCB), 1,2-dichlorobenzene (o-DCB), 1,3-dichlorobenzene (m-DCB) and 1,2,4-trichlorobenzene (TCB) on the dispersion of HiPco SWNTs has been conducted. UV-Vis-NIR absorption spectroscopy coupled with an integrating sphere is employed to differentiate absorbance and scattering. An investigation of the effect of sonication time on sample preparation shows that sonication has a significant effect on the dispersion of SWNTs in organic solvents. The effect of centrifugation of the samples is also explored. For each solvent, a concentration dependent study demonstrates a clear transition between aggregates and dispersed tubes. A critical examination of the efficacy of the solvents in dispersing and solubilising the nanotubes is presented. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim