Structures of Water Molecules in Carbon Nanotubes Induced with Electric Fields and its Application for Water-Methanol Separation

2016 ◽  
Vol 842 ◽  
pp. 453-456 ◽  
Author(s):  
Winarto ◽  
Daisuke Takaiwa ◽  
Eiji Yamamoto ◽  
Kenji Yasuoka
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Electric Field ◽  
Electric Fields ◽  
Electrostatic Interaction ◽  
Water Molecules ◽  
Ordered Structures ◽  
Separation Effect ◽  
Wide Range ◽  
Dynamics Simulations

Water confined in carbon nanotubes (CNTs) under the influence of an electric field has interesting properties that are potential for nanofluidic-based applications. With molecular dynamics simulations, this work shows that the electric field induces formation of ordered structures of water molecules in the CNTs. Formation of the ordered structures strengthens the electrostatic interaction between the water molecules. As a result, water strongly prefers to fill CNTs over methanol and it produces a separation effect. Interestingly, the separation effect with the electric field does not decrease for a wide range of CNT diameter.

scholarly journals Origin of the enhanced structural and reorientational relaxation rates in the presence of relatively weak dc electric fields

2004 ◽  
Vol 76 (1) ◽  
pp. 215-221 ◽  
Author(s):  
A. Vegiri
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Electric Fields ◽  
Structural Relaxation ◽  
Structural Changes ◽  
Common Mechanism ◽  
Weak Electric Field ◽  
Water Molecules ◽  
Relaxation Rates ◽  
Dynamics Simulations

The origin of the dramatic increase of the reorientational and structural relaxation rates of single water molecules in clusters of size N = 16, 32, and 64 at T = 200 K, under the influence of an external, relatively weak electric field (~0.5 107 V/cm) is examined through molecular dynamics simulations. The observed effect is attributed not to any profound structural changes, but to the increase of the size of the molecular cage. The response of water to an electric field in this range shows many similarities with the dynamics of water under low pressure. By referring to simulations and experiments from the literature, we show that in both cases the observed effects are dictated by a common mechanism.

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

Nanoscale ◽  
2016 ◽  
Vol 8 (4) ◽  
pp. 1886-1891 ◽  
Author(s):  
Qi-Lin Zhang ◽  
Rong-Yao Yang ◽  
Wei-Zhou Jiang ◽  
Zi-Qian Huang
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Electric Field ◽  
Molecular Dynamics Simulations ◽  
Electric Fields ◽  
Far Infrared ◽  
Single Walled Carbon Nanotubes ◽  
Frequency Range ◽  
Dynamics Simulations ◽  
Walled Carbon Nanotubes

Using molecular dynamics simulations, we demonstrate that the water channeling across single-walled carbon nanotubes can greatly be affected by the terahertz electric field through the resonant mechanisms induced by various vortical modes in a broad frequency range.

Molecular dynamics simulations of electric field induced water flow inside a carbon nanotorus: a molecular cyclotron

2017 ◽  
Vol 19 (19) ◽  
pp. 12384-12393 ◽  
Author(s):  
Hassan Sabzyan ◽  
Maryam Kowsar
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Molecular Dynamics Simulations ◽  
Water Flow ◽  
Electric Fields ◽  
Water Molecules ◽  
Dynamics Simulations

A nano-flow is induced by applying gigahertz rotating electric fields (EFs) of different strengths and frequencies on a carbon nanotorus filled with water molecules, using molecular dynamics simulations.

Molecular Dynamics Studies of Nanotube Growth in a Carbon ARC

1994 ◽  
Vol 359 ◽  
Author(s):  
C. J. Brabec ◽  
A. Maiti ◽  
C. Roland ◽  
J. Bernholc
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Electric Fields ◽  
Arc Discharge ◽  
Critical Diameter ◽  
Critical Factor ◽  
Carbon Arc ◽  
Dynamics Simulations ◽  
Nanotube Growth ◽  
Brenner Potential

ABSTRACTIt has been shown experimentally that the growth of carbon nanotubes in an arc discharge is open-ended. This is surprising, because dangling bonds at the end of open tubes make the closed tube geometry more favorable energetically. Recently, it has been proposed that the large electric fields present at the tip of tube is the critical factor that keeps the tube open. We have studied the effects of the electric field on the growth of the nanotubes via ab initio molecular dynamics simulations. Surprisingly, it is found that the electric field cannot play a significant role in keeping the tubes open, implying that some other mechanism must be important. Extensive studies of the energetics and simulations of the growth of tubes were performed using a threebody Tersoff-Brenner potential. Our results show that there exists a critical diameter of ∼ 3 nm above which a defect-free growth of a straight tubule is possible. Narrower tubes stabilize configurations with adjacent pentagons that lead to tube-closure and termination of the growth. This explains the absence of tube narrower than 2.2 nm in arc discharge experiments.

Hormones Nanofiltration in Carbon Nanotubes and Boron Nitride Nanotubes Using Uniform External Electric Field Through Molecular Dynamics

2021 ◽  
Vol 21 (11) ◽  
pp. 5499-5509
Author(s):  
Rosely Maria dos Santos Cavaleiro ◽  
Tiago da Silva Arouche ◽  
Phelipe Seiichi Martins Tanoue ◽  
Tais Souza Sá Pereira ◽  
Raul Nunes de Carvalho Junior ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Boron Nitride ◽  
Electric Field ◽  
Field Potential ◽  
Boron Nitride Nanotubes ◽  
Attractive Potential ◽  
Water Molecules ◽  
Computer Simulation Study ◽  
Simulation Time

Hormones are a dangerous group of molecules that can cause harm to humans. This study based on classical molecular dynamics proposes the nanofiltration of wastewater contaminated by hormones from a computer simulation study, in which the water and the hormone were filtered in two single-walled nanotube compositions. The calculations were carried out by changing the intensities of the electric field that acted as a force exerting pressure on the filtration along the nanotube, in the simulation time of 100 ps. The hormones studied were estrone, estradiol, estriol, progesterone, ethinylestradiol, diethylbestrol, and levonorgestrel in carbon nanotubes (CNTs) and boron nitride (BNNTs). The most efficient nanofiltrations were for fields with low intensities in the order of 10-8 au and 10-7 au. The studied nanotubes can be used in membranes for nanofiltration in water treatment plants due to the evanescent field potential caused by the action of the electric field inside. Our data showed that the action of EF in conjunction with the van der Walls forces of the nanotubes is sufficient to generate the attractive potential. Evaluating the transport of water molecules in CNTs and BNNTs, under the influence of the electric field, a sequence of simulations with the same boundary conditions was carried out, seeking to know the percentage of water molecules filtered in the nanotubes.

scholarly journals Molecular Dynamics Simulations of Liquid-Liquid Interfaces in an Electric Field: the Water-1,2-Dichloroethane Interface

2020 ◽  
Author(s):  
Paolo Raiteri ◽  
Peter Kraus ◽  
Julian Gale
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Molecular Dynamics Simulations ◽  
External Electric Field ◽  
Electric Fields ◽  
Liquid Interfaces ◽  
Ewald Summation ◽  
External Electric Fields ◽  
Simulation Cell ◽  
Dynamics Simulations

Molecular dynamics simulations of the liquid-liquid interface between water and 1,2-Dichloroethane in the presence of weak external electric fields.<div>The effect of the use of 3D periodic Ewald summation and the effect of the simulation setup are discussed.</div><div>A new simple geometric method for designing the simulation cell is proposed. This method was thoroughly tested shown that it mitigates any artefacts to the use of 3D Ewald summation with external electric field.</div>

scholarly journals Separation of water–ethanol solutions with carbon nanotubes and electric fields

2016 ◽  
Vol 18 (48) ◽  
pp. 33310-33319 ◽  
Author(s):  
Winarto Winarto ◽  
Daisuke Takaiwa ◽  
Eiji Yamamoto ◽  
Kenji Yasuoka
Keyword(s):  
Carbon Nanotubes ◽  
Electric Field ◽  
Electric Fields ◽  
Electrostatic Interactions ◽  
Water Molecules ◽  
Ordered Structure

Under an electric field, water prefers to fill CNTs over ethanol, and electrostatic interactions within the ordered structure of the water molecules determine the separation effects.

Molecular Dynamics Simulations of the Conductivity of Aqueous NaCl in the Presence of Sucrose and Electric Fields

2014 ◽  
Vol 937 ◽  
pp. 200-206
Author(s):  
Xiao Gang Li ◽  
Shu Ai Yang ◽  
Ming Jun Tang ◽  
Jing Lei ◽  
Hui Hu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Electric Fields ◽  
Ion Pairs ◽  
Water Molecules ◽  
Flashover Voltage ◽  
Low Humidity ◽  
Natural Contamination ◽  
Dynamics Simulations ◽  
Contact Ion Pairs

Various natural contamination components distributed on the surface of high-voltage insulators play important roles on the flashover hazard. Under the low humidity condition, the flashover voltage could be affected considerably by the sucrose contaminations. Molecular dynamics simulations have been carried out in order to reveal the microscopic mechanisms for the sucrose-involved flashover uptake. It is found that the diffusion of ions decreases significantly and thus the conductivity of aqueous medium is lowered apparently. In the presence of sucrose, the contact ion pairs formed between Na+ and Cl- ions are enhanced because both ions are less coordinated to water molecules. The influence of the external electric fields on the diffusion and conductivity were investigated as well. It is suggested that the sucrose contamination might lead to the uneven electric fields on the insulator surface.

scholarly journals Molecular Dynamics Simulations of Liquid-Liquid Interfaces in an Electric Field: the Water-1,2-Dichloroethane Interface

2020 ◽  
Author(s):  
Paolo Raiteri ◽  
Peter Kraus ◽  
Julian Gale
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Molecular Dynamics Simulations ◽  
External Electric Field ◽  
Electric Fields ◽  
Liquid Interfaces ◽  
Ewald Summation ◽  
External Electric Fields ◽  
Simulation Cell ◽  
Dynamics Simulations

Molecular dynamics simulations of the liquid-liquid interface between water and 1,2-Dichloroethane in the presence of weak external electric fields.<div>The effect of the use of 3D periodic Ewald summation and the effect of the simulation setup are discussed.</div><div>A new simple geometric method for designing the simulation cell is proposed. This method was thoroughly tested shown that it mitigates any artefacts to the use of 3D Ewald summation with external electric field.</div>

scholarly journals Electric fields can control the transport of water in carbon nanotubes

2016 ◽  
Vol 374 (2060) ◽  
pp. 20150025 ◽  
Author(s):  
Konstantinos Ritos ◽  
Matthew K. Borg ◽  
Nigel J. Mottram ◽  
Jason M. Reese
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Liquid Crystal ◽  
Carbon Nanotube ◽  
Electric Field ◽  
Electric Fields ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Molecular Ordering ◽  
Technological Interest

The properties of water confined inside nanotubes are of considerable scientific and technological interest. We use molecular dynamics to investigate the structure and average orientation of water flowing within a carbon nanotube. We find that water exhibits biaxial paranematic liquid crystal ordering both within the nanotube and close to its ends. This preferred molecular ordering is enhanced when an axial electric field is applied, affecting the water flow rate through the nanotube. A spatially patterned electric field can minimize nanotube entrance effects and significantly increase the flow rate.

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