Efficient dispersing and shortening of super-growth carbon nanotubes by ultrasonic treatment with ceramic balls and surfactants

A low-power ultrasonic treatment together with ceramic balls was applied to disperse and shorten super-growth carbon nanotubes (SG-CNTs) in aqueous solutions containing an anionic surfactant, sodium deoxycholate (SDC) or a polymeric nonionic surfactant, tocopheryl PEG 1000 succinate (TPGS). With this mild treatment, the long tubes of as-received SG-CNTs (>200 μm) were efficiently and significantly shortened to below about 1 μm after the treatment. In the same time, the shortened SG-CNTs were well-dispersed in aqueous medium to form stable SG-CNTs solutions containing relatively high SG-CNTs concentration (>0.1% w/v).