Supramolecular Interactions of High Molecular Weight Poly(2,7-carbazole)s with Single-Walled Carbon Nanotubes

A novel 2,7-carbazole monomer unit was synthesized and used to prepare two poly(2,7-carbazole)s, both of which were obtained in relatively high molecular weight and display excellent solubility in common organic solvents. The polymers were able to effectively disperse carbon nanotube bundles in both THF and toluene using a relatively simple procedure to yield concentrated polymer–carbon nanotube samples that were stable for months. The polymer-coated carbon nanotube samples were characterized by thermogravimetric analysis, atomic force microscopy, absorption spectroscopy, photoluminescence mapping, and Raman spectroscopy. It was found that the polymers used in this study preferentially interact with carbon nanotubes having diameters of 1.15 nm or less. Additionally, it was observed that the carbon nanotubes remained effectively debundled by the polymers after removal of solvent, as was demonstrated by Raman and photoluminescence mapping of solid films of the polymer–carbon nanotube composites.