Water jumps over a nanogap between two disjoint carbon nanotubes assisted by thermal fluctuation

Temperature determines thermal fluctuations of molecules on the nanoscale, and thus should be essential to the nanofluidic transport. Despite of considerable work in the context of nanofluidic transport, most of previous work focus on the carbon nanotubes (CNTs) with intact structures, the broken CNTs are rarely explored. In this work, we investigate the transport of single-file water molecules through two disjoint CNTs with a nanogap by molecular dynamics simulations. At room temperature, with the increase in nanogap length, the water flow exhibits a sudden decrease to zero, suggesting an excellent on-off gate. This is because for large nanogaps, the single-file water chain will be breakdown, which also results in the reduction in water occupancy and hydrogen bond number. The water translocation time, dipole orientation and flipping frequency, as well as density profiles are also found to be dependent on the CNT nanogap. More interestingly, rising the temperature significantly promotes the water jumping over large nanogaps, where the water flow exhibits a monotonous increase. These results are helpful for the design of nanoscale devices with gap structures, particularly nanofluidic gates. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study investigates the transport of water molecules through two disjoint carbon nanotubes with a nanogap using molecular dynamics simulations. The results show that temperature and nanogap length significantly affect the water flow, which is important for the design of nanoscale devices.