Direct measurements of the Young's modulus of a single halloysite nanotube using a transmission electron microscope with a bending stage.

Halloysite nanotubes (HNTs) are a naturally occurring nanotubular aluminosilicate mineral, which has been used to prepare nanocomposites with exceptional mechanical properties. In order to understand the roles of nanotubes during the deformation and fracture of nanocomposites, a state-of-the-art transmission electron microscope (TEM) with a bending stage was used to measure the Young's modulus of individual HNTs. TEM micrographs showed that the HNTs were surprising flexible and could be bent to almost 90 degrees without fracture. There was no observable reduction in the cross-sectional area of the bent HNTs. The findings suggest that HNTs, as a nanofiller, have a good potential to be used in high-performance structural materials, especially polymer-based nanocomposites.