We have observed concentration dependent exfoliation of single-walled carbon nanotubes dispersed in solutions of the synthetic peptide nano-1. As the nanotube concentration is reduced, the bundle diameters tend to decrease before saturating at <2.0 nm for concentrations below 6 x 10(-3) mg/mL. The fraction of individual nanotubes increases with decreasing concentration, saturating at approximately 95% at low concentration. This concentration dependent exfoliation happens even if the dispersions are not sonicated on dilution, albeit over a longer time scale. The populations both of individual nanotubes and of bundles are much higher than expected at high concentrations, indicating the presence of repulsive internanotube interactions stabilizing the dispersions.
Trinity College Dublin ->