Temperature and pH-responsive single-walled carbon nanotube dispersions.

Solubilization of single-walled carbon nanotubes (SWNTs) using noncovalently interacting polymer surfactants in aqueous media has opened up a new vista of SWNTs in biology and medicine. In many potential applications, it is desirable to control the dispersion or aggregation of SWNTs in solvents with external stimuli. Here we report two "smart" SWNT dispersions that respond to temperature and pH changes in poly(N-isopropylacrylamide) and poly-L-lysine solutions.