Polymer conformation-assisted wrapping of single-walled carbon nanotube: The impact of cis-vinylene linkage

A soluble π-conjugated polymer cis-PmPV is found to be twice as effective as its trans-PmPV isomer in dispersing SWNTs into organic solvents. The improved efficiency is related to the specific conformation of cis-vinylene-enriched PmPV, which facilitates a planar π-π interaction with SWNT surface and leads to improved nanotube dispersion. 1H NMR spectra indicate that the cis-CHCH bonds are partially converted to the trans-CHCH, thereby providing necessary conformational cavity for SWNT wrapping. Irradiation triggers a precipitation from SWNT dispersion, providing a purified SWNT/conjugated polymer composite.