Covalent cross-linked polymer/single-wall carbon nanotube multilayer films

Layer-by-layer films have been constructed from a cationic diazoresin and poly(sodium 4-styrene-sulfonate)-functionalized single-wall carbon nanotubes (SWNT). Raman and near-IR absorption spectra indicate that some diazonium ions reacted with SWNT during film construction. The ionic bonds in the film between diazonium ions and sulfonate ions converted to covalent bonds upon UV irradiation as shown by the disappearance of diazonium ion peaks in the UV and IR spectra and appearance of an arenesulfonate peak in the IR spectra. The resistance of the film toward etching by polar solvents increased significantly after irradiation.