An environmentally friendly approach to functionalizing carbon nanotubes for fabricating a strong biocomposite Film

Water-soluble, highly functionalized multiwalled carbon nanotubes (MWNTs) were prepared viaa facile, environmentally benign method. The effectiveness of the highly functionalized MWNTs as a reinforcing filler in a water-soluble mechanically weak chitosan biopolymer was evaluated. We observed a substantial improvement in the mechanical properties of the film; the stretchability of the film was maintained when 5 wt% MWNTs was added. In addition, the biocomposite film exhibited long-term antibacterial activity. The reinforcing effect can be explained by the homogeneous dispersion of the nanotubes in the polymer matrix through the strong hydrogen bonding between the sulfonic acid groups (-SO sub(3)H) on the sidewalls of the MWNTs and the amine (-NH sub(2)) and hydroxyl (-OH) groups on the chitosan backbone. The improvement in the mechanical properties of the MWNT-chitosan biocomposite may make it suitable for many environmental and clinical applications.