Nematic ordering of SWNT in meso-structured thin liquid films of polystyrenesulfonate
Racheli Itzhak-Cohen1, Einat Nativ-Roth, Yael Levi-Kalisman
1Department of Chemical Engineering, ‡The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev , Beer Sheva 84105, Israel.
Abstract:
The formation of nematic-like islands of single-walled carbon nanotubes (SWNT) in polystyrenesulfonate (PSS) dispersions confined into nanometrically thin films is reported. The SWNT are observed to assemble into orientationally ordered phases, where the intertube distance, as measured via transmission electron microscopy at cryogenic temperatures, matches the polyelectrolyte's bulk correlation length deduced from X-ray scattering. The micrometers-long islands of orientationally ordered carbon nanotubes are observed in both SWNT and double-walled carbon nanotubes (DWNT) but not in specimens prepared from similar dispersions of multiwalled carbon nanotubes (MWNT). These observations, together with relaxation and rheological experiments, suggest that the orientational ordering may result from coupling between confinement of the polymer-wrapped SWNT and DWNT and the microstructure of the solvated polyelectrolyte.
