Structural changes in carbon nanofibers induced by ball milling

A nested cones type carbon nanofiber (CNF) was exposed to ball milling with different milling times. Ball milled CNFs were investigated by transmission electron microscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis. It was suggested that the milling energy could be consumed by CNF grinding and aggregating. The effect of mechanical stress causes a “flattening” of the CNFs with the loss of the nanofibrous structure, and the amount of carbon layers in crystallite decreases. Multiple structural changes induced by ball milling lead to fluctuations of sp3/sp2 and O/C ratios.