Abstract: Dispersible single-walled and multi-walled carbon nanotubes (CNTs) are prepared by dissolving surfactants in water to form a solution; adding carbon nanotubes to the solution to form a mixture; sonicating and agitating the mixture to form a carbon-nanotube/water dispersion; centrifuging the dispersion to remove un-dispersed carbon nanotubes and impurities; repeatedly freezing and heating the CNT dispersion; and, sublimating water in the CNT dispersion by freezing and evacuating the dispersion to obtain carbon nanotubes coated with surfactant. The carbon nanotubes prepared by the method of the invention are dry, amphiphilic, and surfactant-coated powders that can be dispersed in both aqueous and organic solvents to form stable and uniform dispersions having a high concentration of carbon nanotubes.