Thermally triggered nanorocket from double-walled carbon nanotube in water

ABSTRACT

In this work, we propose and investigate the use of double-walled carbon nanotubes (DWCNTs) as nanosized rockets. The nanotubes are immersed in water, and the propulsion of inner nanotube is achieved by heating the water encapsulated within the DWCNT. Considering a setup made of (5,5)(8,8) DWCNT, molecular dynamics simulations for different water temperatures show that the trajectory can be divided into four phases: trigger, expulsion, damping and final equilibrium. After analysing the dynamics and the involved forces, we find out that the inner nanotube expulsion is mainly controlled by van der Waals interactions between the nanotubes; whereas, the damping role is predominantly played by the external aqueous environment. Based on these results, we propose an analytical model able to predict both the triggering time for a given water temperature and the whole dynamics of nanorocket. The validity of such dynamical model can be extended also to a broader variety of DWCNT configurations, once the different forces acting on the inner nanotube are provided. The proposed model may contribute to assist the design of nanorockets in several nanotechnology applications, such as triggered drug delivery, cell membrane piercing, or colloids with thermophoretic properties.

KEYWORDS:

• Nanomotor
• double-walled carbon nanotube
• nanotube
• nanorocket
• water

Acknowledgments

We are grateful to Mustafa Hamad for performing preliminary simulations.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Matteo Fasano http://orcid.org/0000-0002-3997-3681

Pietro Asinari http://orcid.org/0000-0003-1814-3846

Additional information

Funding

The authors would like to acknowledge the financial support from the Italian ‘Fondazione Cassa Risparmio Torino’ (CRT) under the project NANOSTEP (‘La Ricerca dei Talenti’ call, grant number: 911/2015). Authors thank the HPC initiative at Politecnico di Torino (DAUIN) and CINECA for the high performance computing resources under the IscraC projects MISURPAC (grant number: HP10CJOR5E) and NANOCLUS (grant number: HP10CYC6UC).