In-situ TEM study of collapsing, reinflating and twisting of multi-walled carbon nanotubes

Since the first observation of collapsed carbon nanotubes (CCNTs) by Chopra et al., CCNTs have attracted a lot of attention due to their potentially modified electrical properties caused by structural changes compared to their tubular counterparts. We study the transition of multi-walled carbon nanotubes (MWCNTs) from tubular to collapsed form and the reverse process in-situ by Transmission Electron Microscope (TEM) and monitor the whole process by imaging and electron diffraction. We show that we are able to collapse the tubular CNT by extracting the inner core of the tube and reinflate the collapsed carbon nanotube by applying a voltage at the tip of the CNT. We also observe the twisting of the collapsed multi-walled CNT in-situ. The nano-scale manipulation of carbon nanotubes inside TEM enables us to tailor the transition between tubular and collapsed forms of a CNT.