Preparation of Polymeric SWNT−Liquid Crystal Composites Using a Polymerizable Surfactant

Polymeric carbon nanotube (CNT)−liquid crystal composites were prepared using single-walled CNTs (SWNTs) and a polymerizable surfactant (dodecyldimethylammonium ethyl methacrylate, DDAM). The pristine SWNTs were dispersed in a lyotropic liquid crystal (LC) of DDAM (70 wt % in water). The bare lyotropic LC of DDAM and the dispersions showed columnar hexagonal phases. In X-ray diffraction analysis, the d-spacings were increased as the pristine SWNT concentration was increased up to 0.15 wt %, indicating that the pristine nanotubes were well incorporated in the hexagonal LC phase where they induced a swelling of the structure. The dispersions were photopolymerized to give polymeric composites. With increasing pristine SWNT concentration, the electrical resistivities of the composites continuously decreased, while their dielectric constants increased. The method reported herein provides a facile way to prepare a polymeric CNT−LC composite that combines the properties of both LCs and SWNTs.