(279g) Measurements of Competitive Surfactant Adsorption On a Dispersed Nanotube

The effects of competitive surfactant adsorption on the buoyancy of chirality resolved dispersed single-wall carbon nanotubes will be presented. As nanoparticles with well defined surface structures, chirally resolved nanotubes are an ideal test bed for the measurement of nanoparticle structure effects on an adsorbed surfactant layer. Analytical ultracentrifugation, which enables direct observation of a dispersed particle's buoyancy through its location in a density gradient is supported by spectroscopic measurements in these studies. Specific effects of surfactant concentration, structure, and solution environment will be considered. Resolution of the buoyancy values as a function of these parameters will allow for the rational development of nanotube separation schemes involving centrifugation and/or adsorbed layer properties.