High energy ball milling of catalytically synthesized carbon nanotubes

This study examines the ball-milling of CVD-processed multi-wall carbon nanotubes for cutting and opening their tips. Results show that dry milling causes nanotubes to rapidly collapse, hence transforming into graphite structure, while wet milling with some organic compounds effectively shortened and opened the nanotubes. Carbon-based milling agents are known to alter surface structure of carbon nanotubes, minimizing an excess algglomeration and consequently improving dispersion of nanotubes. The open tip structure was unstable and quite susceptible to re-close during milling and thermal treatments to minimize their surface energy.