Small angle neutron scattering from single-wall carbon nanotube suspensions: evidence for isolated rigid rods and rod networks

We report small angle neutron scattering (SANS) from dilute suspensions of purified individual single wall carbon nanotubes (SWNTs) in D2O with added sodium dodecylbenzene sulfonate (NaDDBS) ionic surfactant. The scattered intensity scales as Q-1 for scattered wave vector, Q, in the range 0.005 < Q < 0.02 Å-1. The Q-1 behavior is characteristic of isolated rigid rods. A crossover of the scattered intensity power law dependence from Q-1 to Q-2 is observed at ~0.004 Å-1, suggesting the SWNTs form a loose network at 0.1 wt% with a mesh size of ~160 nm. SANS profiles from several other dispersions of SWNTs do not exhibit isolated rigid rod behavior; evidently the SWNTs in these systems are not isolated and form aggregates. Comments Postprint version. Published in Chemical Physics Letters, Volume 384, Issues 1-3, 19 January 2004, pages 185-189. Publisher URL: http://dx.doi.org/10.1016/j.cplett.2003.11.106 Author(s) Wei Zhou, M. F. Islam, H. Wang, D. L. Ho, A. G. Yodh, Karen I. Winey, and John E. Fischer This journal article is available at ScholarlyCommons: http://repository.upenn.edu/mse_papers/61 Small angle neutron scattering from single-wall carbon nanotube suspensions: evidence for isolated rigid rods and rod networks W. Zhou a,c , M. F. Islam b,c , H. Wang d , D. L. Ho e , A. G. Yodh b,c , K. I. Winey a,c and