Grafting of poly(4-vinylpyridine) to single-walled carbon nanotubes and assembly of multilayer films

Poly(4-vinylpyridine) grafts to single-walled carbon nanotubes (SWNT) during in situ free radical polymerization of 4-vinylpyridine. After removal of catalyst particles and unattached polymer by centrifugation and ultrafiltration, the SWNT-PVP contains about 63 wt % SWNT by TGA. SWNT-PVP solutions in DMF, methanol, and 2-propanol are stable for at least 8 months. Atomic force microscopy images show individual tubes. Raman spectra are consistent with debundled SWNT having PVP covalently attached. Near-infrared (NIR) spectra show band gap electronic transitions of SWNT. Layer by layer deposition of alternating thin films of SWNT-PVP and poly(acrylic acid) (PAA) adds a constant amount of SWNT-PNT in each bilayer. FTIR spectra of the films show hydrogen bonding between the PVP and the PAA.