The extraction of single-walled carbon nanotubes by exploiting the phase transition of poly(N-isopropylacrylamide), a thermoresponsive polymer, was performed to obtain homogenous electronic properties. The semiconducting single-walled carbon nanotubes were selectively extracted into the aqueous phase of a PNIPAM solution above the lower critical solution temperature.

Optimized experimental conditions in the presence of sodium borate achieved the selective release of (6,4) nanotubes into the liquid phase.