Ring-ribbon transition and parallel alignment in SWNT films on polyelectrolytes

A simple and reliable method of permanent organization of SWNTs into morphologically different films is described. Under standard adsorption conditions, SWNTs form films from randomly intersecting nanotubes. It was found that virtually perfect rings from single SWNTs also form spontaneously in these films. Adsorption in laminar flow produces SWNT ribbons with parallel alignment of the nanotubes. Further increase of the flow rate detaches SWNT from the surface.