Summary: The use of the block copolymers polystyrene‐block‐poly(ethylene oxide) and poly(methyl methacrylate)‐block‐poly(ethylene oxide) is described to assist the direct solubilization of single‐walled carbon nanotubes (SWNTs) into water under ultrasonic irradiation. As compared to surfactants and homopolymers, the block copolymer systems may offer the potential of additional unique morphologies through self‐assembly. TEM and AFM analyses of solution‐cast samples indicate exfoliation and wetting of the SWNTs by the block copolymer. With increasing duration of ultrasonic irradiation, an increase in solution viscosity is initially found, which suggests that it is a convenient indicator of the progress of exfoliation of the SWNTs. With continued intense ultrasonic irradiation, the solution viscosity may decrease apparently because of damage/breakage of the SWNTs.
Schematic of the interaction of the PMMA‐b‐PEO block copolymer with the single‐walled carbon nanotubes and the specific viscosity of the system in aqueous solution as a function of sonication time: results from using an ultrasound bath (‐‐‐‐▪‐‐‐‐) or an ultrasound horn (—▴—).
