Enormous Shrinkage of Carbon Nanotubes under Low-Energy Electron Beam Irradiation with Uniaxial Tensile Stress

We found that low-energy electron irradiation combined with uniaxial tensile stress strongly enhanced the shrinkage of carbon nanotubes (CNTs). The shrinking maximized at 5 keV, although some believe that the low-energy electron irradiation from 1 to 30 keV using a scanning electron microscope hardly induces structural deformation of CNTs. Such shrunk CNTs showed periodic and zigzag folding of their sidewalls, resulting in about 90% shrinkage from the original length. Such deformation could be induced in either single- or multi-walled nanotubes (MWNTs). The surface area per unit volume drastically increased up to 560% when a tube shrunk to 10% of its original length, a phenomenon observed in the shrinkage of MWNTs.