Carbon nanotube chirality enrichment through chirality-selective precipitation

The interaction with surfactants changes from one carbon nanotube species to the other. We used this to replace non-ionic surfactants by ionic ones. By fine-tuning the replacement conditions, we covered some specific nanotubes with non-ionic surfactants and the others with ionic ones. Addition of salt triggers precipitation of the species suspended by the ionic surfactant; this effectively leads to chiral selective enrichment of a carbon nanotube suspension. We hence produce an (8,4)-enriched suspension by replacing a polyglycerol-based custom amphiphile with the commercial SDBS and salting with NaCl.