Keywords: double-walled carbon nanotubes, ball milling, nanotechnology, CNT shortening, CNT production, image analysis, fine control, tube length distribution, polymer nanocomposites, CNT toxicology, nanomanufacturing
Shortened double-walled carbon nanotubes by high-energy ball milling
Despite significant scientific interest, there are currently no widely accepted methods for the production or shortening of CNT that offer fine control over CNT length distribution. This paper reports the production of shortened double walled carbon nanotubes (DWNT) by high-energy ball milling and their characterisation via TEM, SEM, Raman, TGA and XPS techniques. Image analysis showed that ball milling was effective at shortening DWNT; however, fine control of the tube length distribution was not possible. The high-energy milling was found to lead to DWNT destruction if samples were processed for longer than 4 min. Ball milling was also found to qualitatively increase amorphous carbon content. A slight increase in side wall oxidation with increased ball milling time was observed via XPS. These well characterised DWNT samples will be employed in polymer nanocomposite and CNT toxicology studies.