The transport of water molecules through nanopores is not only crucial to biological activities but also useful for designing novel nanofluidic devices. Despite considerable effort and progress that has been made, a controllable unidirectional flow still difficult achieve the underlying mechanism far from being understood. In this paper, using molecular dynamics simulations, we systematically investigate effects an external electric field on single-file carbon nanotube (CNT). We find...

Through systematic molecular dynamics simulations we theoretically investigate the potential applications of hexagonal boron nitride (h-BN) for seawater desalination. Our results indicate that rationally designed h-BN membranes have great permeability, selectivity, and controllability water The size chemistry pores are shown to play an important role in regulating flux salt rejection. Pores with only nitrogen atoms on edges higher fluxes than boron-lined pores. In particular, two-dimensional...

Improving the desalination performance of membranes is always in spotlight scientific research; however, Janus channels with polarized surface charge as nanofiltration are still unexplored. In this work, using molecular dynamics simulations, we demonstrate that graphene oxide (GO) appropriate geometry and can serve highly efficient membranes. We observe water permeability symmetric GO significantly superior to asymmetric without sacrificing much ion rejection, owing weakened blockage...

From the perspectives of biological applications and material sciences, it is essential to understand transport properties water molecules through nanochannels. Although considerable effort progress has been made in recent years, a systematic understanding effect nanochannel dimension still lacking. In this paper, we use molecular dynamics (MD) simulations study carbon nanotubes (CNTs) with various dimensions under pressure differences. We find an exponential decay describing relation flow...

Improving the ionic rectification in nanochannels enables versatile applications such as biosensors, energy harvesting, and fluidic diodes. While previous work mostly focused on effect of channel geometry surface charge, this via a series molecular dynamics simulations, we find striking phenomenon that current (ICR) ratio Janus graphene oxide (GO) channels can be tremendously promoted by lateral electric fields. First, under given axial field, an additional field improve ICR several times to...

Osmosis are essential for not only the application of nanofluidic devices but also understanding working principles biological transmembrane proteins. Despite considerable experimental interests, comprehensive simulation work is still lacking, possibly because periodic boundary condition that inevitably leads to spontaneous exchange two side reservoirs. To eliminate this disadvantage, herein we design a simple model system by introducing dipalmitoylphosphatidylcholine bilayer into common...

Liquid crystals playing a crucial role in material sciences show increasing potential applications nanotechnology and industry. Generally, thermodynamic dynamic properties of liquid strongly depend on the corresponding force fields (FF); thus, it is necessary urgent for us to establish reliable field given crystal system. In this paper, we develop new set FF parameters 5CB (4-cyano-4'-pentylbiphenyl) molecule by reoptimizing some TraPPE-UA order reproduce bulk density. This strategy...

Transport properties of water molecules through hydrophobic channels have been explored extensively in recent years; however, our knowledge about the transport hydrophilic is still rather poor. Herein, we use molecular dynamics simulations to study permeation a charged channel. For comparison, first consider pristine channel without charge, and find an analytic expression that can predict flow it. uniformly channels, with increase charge density, decreases, due roughness free energy profile...

Control of water and ion transport through nanochannels is primary importance for the design novel nanofluidic devices. In this work, we use molecular dynamics simulations to systematically analyze coupling ions a carbon nanotube in electric fields. We focus on role ionic conditions, including salt species concentration, which can significantly regulate further transport. find that water–anions stronger than water–cations, thus anions play dominant determining Specifically, flux both exhibit...

Temperature governs the motion of molecules at nanoscale and thus should play an essential role in determining transport water ions through a nanochannel, which is still poorly understood. This work devotes to revealing temperature effect on coupling carbon nanotube by molecular dynamics simulations. A fascinating finding that ion flux order changes from cation > anion with increase field strength, leading same direction change flux. The competition between hydration strength mobility be...

Monolayer ice confined in double-walled carbon nanotubes can be effectively melted using terahertz electric fields.

In this paper, with the aim to establish a rational coarse-grained (CG) model for 4-cyano-4'-pentylbiphenyl (5CB) molecule, we construct three possible CG models (5P, 6P, and 7P) then determine bonded nonbonded interaction parameters separately. For intramolecular interactions, bond angle distributions of 5CB bulk phase are used as target properties. interactions between particles, combine structure-based thermodynamic quantities-based methods parametrization potentials attempt use several...

Understanding the coupling relation between water and ions in their transport through nanochannels is relevant to many physicochemical process biological activities should be preliminary knowledge that nanofluidic devices depend on. This work devoted revealing a (10,10) carbon nanotube under drive of pressure difference. By using extensive molecular dynamics simulations, we compare different salts from monovalent trivalent cations as well salt concentration. An interesting phenomenon...

Reverse osmosis membranes hold great promise for dealing with global water scarcity. However, the trade-off between ion selectivity and permeability is a serious obstacle to desalination. Herein, we introduce an effective strategy enhance desalination performance of membrane. A series molecular dynamics simulations manifest that additional lateral electric field significantly promotes rejection in carbon nanotubes (CNTs) under drive longitudinal pressure. Specifically, increase field, flux...

Controlling the water permeation through carbon nanotubes (CNTs) with more complex structures holds great promise for many practical applications, such as nanometer gates, energy collection, and biosensors. In this work, upon using extensive molecular dynamics simulations, we find a fascinating phenomenon that terahertz electric fields can significantly stimulate transport of single-file chain across two disjoint CNTs nanogap, where flow is several times to an order greater than static...

In an electric field, the orientation and self-assembly mechanisms of carbon nanotubes (CNTs) suspended in aqueous solution are studied by molecular dynamics simulations. It is shown that combination effect confined interface field drives CNTs to orient along direction, process determined competition between CNT–CNT CNT–water interactions. These results not only enrich our knowledge nonpolar nanoparticles, but also pave way for using as a novel tool achieve their self-assembly. particular,...

We use molecular dynamics (MD) simulations to study the transport of single-file water molecules through carbon nanotubes (CNTs) with various lengths in an electric field. Most importantly, we find that even dipoles inside CNT are maintained along field direction, a large amount can still against direction for short CNTs, leading low unidirectional efficiency (η). As length increases, η will increase remarkably, and achieves maximum value 1.0 at or exceeding critical length. Consequently,...

Water and ion transport through graphene nanochannels has attracted considerable attention thanks to the possibility of dimensional control channel sizes down a single atomic layer. Using molecular dynamics simulations, we systematically analyzed coupled water ions in solutions LiCl, NaCl, KCl salts as function sizes, applied electric fields, salt concentrations. A universal order flux is found with K+ > Cl– Na+ ≈ Li+, twice large those indicating selectivity such channels. The local...

Controlling the water transport in a given direction is essential to design of novel nanofluidic devices, which still challenge because thermal fluctuations on nanoscale. In this work, we find an interesting electropumping phenomenon for charge-modified carbon nanotubes (CNTs) through series molecular dynamics simulations. electric fields, flowing counterions CNT inner surface provide direct driving force conduction. Specifically, cations and anions exhibit distinct behaviors that lead...

Understanding the electroosmotic flow through a nanochannel is essential to design of novel nanofluidic devices, ranging from desalination nanometer water pumps. Nonetheless, competition between cation and anion in electric fields inevitably leads limited pumping water, thus weakening their could be new avenue for fundamental control transport. In this work, series molecular dynamics simulations, we find surprising phenomenon which under drive traditional longitudinal field, an additional...

Inspired by the high water permeability and excellent salt rejection of hourglass-shape aquaporin channels, asymmetric channels have attracted increasing attention in recent years. In this work, we use molecular dynamics simulations to explore transport an ionic solution through graphene under a pressure difference. We observe interesting desalination phenomenon when changing channel geometry. Specifically, fluxes ions convergent direction are larger than those divergent direction; however,...