Multiwall nanotubes and fullerene-like nanoparticles of WS₂ are produced in large amounts, offering numerous opportunities for their investigation and future applications. While many studies focus on the preparation and studying the characteristics of bulk matrices incorporating these nanotubes, the investigation of individual nanotubes permits addressing intriguing issues, encompassing their unique optical, electrical and mechanical properties.

In this report, the author will dwell on several new studies. FET of WS₂ nanotubes with liquid ionic gating demonstrated that the nanotubes become superconducting at low temperatures (5.8 K).¹ The magnetoresisitance exhibited strong Little-Parks oscillations under magnetic field parallel to the tube axis, which originates from the interference of the supercurrent along the circumference of the nanotube. The coupling of the supercurrent with the magnetic field in the chiral tubes produces nonreciprocal second harmonic signal.

In another study, the electromechanical characteristics of a torsion device based on single nanotube was studied.² A high frequency resonator with high quality factor was established. The high quality factor of the WS₂-based device was attributed to the interlocking of the layers, which minimize the dissipative losses due to reciprocating motion of the nanotubes walls during torsion.

The wetting of single WS₂ nanotube retracted from a liquid surface was studied experimentally and by detailed computational anlaysis.³  Nanotubes with different diameter and having open or closed tips were studied. It was found that the water does not wet the outer wall of the nanotubes. However, nanotubes with open end of diameter below say 40 nm exhibited strong interaction with the water surface. Careful analyses indicated that strong capillary action leads to the filling of the hollow nanotube core which leads to large dissipated energy during withdrawal of the nanotube.

At the end of the talk, the author will briefly deliberate on the commercial applications of fullerene-like WS₂ nanoparticles in advanced lubrication and the industrial prospects of nanotubes thereof.

References

1. F. Qin, W. Shi, T. Ideue, M. Yoshida, A. Zak, R. Tenne, T. Kikitsu, D. Inoue, D. Hashizume, and Y. Iwasa, Nature Comm., DOI: 10.1038/ncomms14465 (2017).

2. Y. Divon, R. Levi, J. Garel, D. Golberg, R. Tenne, A. Ya’akobovitz and E. Joselevich, Nano Lett. 17, 28-35 (2017).

3. O. Goldbart, S.R. Cohen, I. Kaplan-Ashiri, P. Glazyrina, H.D. Wagner, A. Enyashin and R. Tenne, Proc. US Natl. Acad. Sci. (PNAS) 113, 13624-13629 (2016).