Controllable Water Channel Gating of Nanometer Dimensions

Abstract

The dynamics of water molecules in a single-walled carbon nanotube (SWNT) under continuous deformations was studied with molecular dynamics simulations. The flux and occupancy remain almost fixed within a deformation of 2.0 A but decrease sharply for a further deformation of 0.6 A. The nanopore is an excellent on-off gate that is both effectively resistant to deformation noises and sensitive to available signals. Biological water channels are expected to share this advantage due to similar wavelike water distributions. The minimal external force required for triggering an open-close transition falls within the working range of many available experimental facilities, which provides the possibility of developing SWNT-based nanoscale devices.

Fast water channeling across carbon nanotubes in far infrared terahertz electric fields

“…1. An uncapped (6,6) armchair SWCNT with a length of 1.34 nm and a diameter of 0.81 nm is embedded in two parallel graphite sheets along the z direction. The distance between the bottom end of the SWCNT and the graphite sheet is 2…”

“…An uncapped (6,6) armchair SWCNT combined with two graphite sheets is solvated in a water box of 3.5×3.5×6.3nm…”

“…Indeed, one important reason why research on nanochannel transport properties has continued to be of interest is that many primary characteristics of water confined in simple nanochannels are similar to that of complex biological channels [1][2][3][4][5][6][7] . In the past, the water transport properties have been studied extensively in singlewalled carbon nanotubes (SWCNTs) [8][9][10][11][12] .…”

Transport properties and induced voltage in the structure of water-filled single-walled boron-nitrogen nanotubes

“…Consequently a pressure gradient was induced between the two ends of a SWBNNT. Following the method proposed by Zhu et al 20 and examined by Wan et al 21 and Li et al, 22 an external force along the nanotube +z axial direction was applied to the O atoms of water molecules whose coordinates ͑in the unit cell of the periodic system͒ satisfy 0 Ͻ z Ͻ 8 Å in our simulation. The corresponding pressure is 150 MPa.…”

Rapid Transport of Water via a Carbon Nanotube Syringe

“…Additionally, small deformations do not significantly affect flux, but any deformation beyond a critical amount will cause a reduction of flux. 13 Alternatively, mobile charges located outside the carbon nanotubes can induce an ordering of the water molecules along the nanotube channel facilitating the flow of water molecules; this can increase the magnitude of the flow by a factor 20.…”