Helical Wrapping of Single-Walled Carbon Nanotubes by Water Soluble Poly( p -phenyleneethynylene)

1. Helical Wrapping of Single-Walled Carbon Nanotubes by Water Soluble Poly(p-phenyleneethynylene) Dawn A. Bonnell, University of Pennsylvania, DMR 0425780 Amphiphilic, linear conjugated poly[p-{2,5-bis(3-propoxysulfonicacidsodiumsalt)} phenylene]ethynylenes, PPES efficiently disperse SWNTs into water via helically wrapping on the tube surface PPES (a, b) Tapping mode AFM image and height profile histogram of highly individualized PPES-SWNT. (c, d, e) AFM image and height profile of small PPES-SWNT bundles showing periodic helical wrapping of PPES on SWNT surface Vis-NIR absorption spectra of PPES-SWNT suspensions under long and short time sonication process; comparison with a SDS-SWNT suspension indicates highly individualized SWNTs dispersed by PPES in water. Conclusion: (i) PPES, a linear conjugated polymer, disperse individualized SWNT in water. (ii) PPES wraps SWNT forming a self-assembled helical superstructure with a pitch of 13±2 nm predicted by MD simulation Snapshots of the interaction process between a (10, 0) SWNT and a 20-mer PPES over 1-20 ns period