Double Stimuli-Responsive Copolymer Stabilizers for Multiwalled Carbon Nanotubes.

A unique copolymer stabilizer is presented that can be used to stabilize multiwalled carbon nanotubes in aqueous solution to form "smart" dispersions. They showed double stimuli-responsive behavior (in dependence of temperature and ionic strength) and allowed for accurate control of the transition (exfoliated → agglomerated) temperature of nanotubes over a wide temperature range. In spite of its effective dispersion strength, the copolymer was easily synthesized in one step via free radical copolymerization of N -isopropylacrylamide and 1-ethyl-3-vinylimidazolium bromide.