Surfactant Assisted Incorporation of Single-Walled Carbon Nanotubes into a Chitosan-Polyvinylpyrrolidone Polymer

A novel method for the incorporation of highly dispersed single-walled carbon nanotubes (SWNTs) into a chitosan matrix is reported. This was achieved through the use of a precursor SWNT dispersion in a biocompatible surfactant solution containing cetyl trimethylammonium bromide (CTAB) and polyvinylpyrrolidone (PVP). Once a desirable degree of dispersion was attained this precursor SWNT dispersion was mixed with a chitosan solution followed by chemical crosslinking of the chitosan. Vis/NIR and Raman spectra of several sections of the resulting solid nanocomposite material suggested uniform dispersion of SWNTs throughout the solid matrix. The mechanical properties of the nanocomposite were tested and compared to a material obtained using a similar protocol without the use of SWNTs. The results indicate that the presence of a relatively low amount (0.32 wt%) of SWNTs is enough to significantly increase the stiffness and elastic modulus of uncrosslinked chitosan by over 20 times.