Molecular Insights into Hybrid CH Physisorption-Hydrate Formation in Spiral Halloysite Nanotubes: Implications for Energy Storage.

A microscopic insight into hybrid CH physisorption-hydrate formation in halloysite nanotubes (HNTs) is vital for understanding the solidification storage of natural gas in the HNTs and developing energy storage technology. Herein, large-scale microsecond classical molecular dynamics simulations are conducted to investigate CH storage in the HNTs via the adsorption-hydration hybrid (AHH) method to reveal the effect of gas-water ratio. The simulation results indicate that the HNTs are excellent nanomaterials for CH storage via the adsorption-hydration hybrid method.

Transport Properties of Aqueous Methane Solutions and Blocking Behavior of Intelligent-Responsive Temporary Plugging Agent in a Switchable Nano-channel: A Dissipative Particle Dynamics Simulation Study.

Intelligent-responsive temporary plugging agents (TPAs) have great potential in the field of oil and gas resource extraction due to their self-adaptability to the environment. However, the transport mechanism of oil and gas molecules, such as aqueous methane solution in intelligent-responsive TPA-modified nano-channels and the blocking behavior of TPA, have not been verified yet. In this work, dissipative particle dynamics simulations (DPD) are conducted to investigate the velocity distribution and the force characteristics of aqueous methane solutions under different driving velocities, as well as the blocking effect of TPA to the flow of solution.

Effects of marine environments on methane hydrate formation in clay nanopores: A molecular dynamics study.

In nature, CH hydrates are mainly buried in marine sediments. The complex marine environments on the seafloor continuously affect hydrate formation. Herein, systematic molecular simulations have been performed to investigate CH hydrate formation in clay nanopore, mainly affected by several marine environmental factors, including seawater salinity, pressure and temperature.

Effects of surface property of mixed clays on methane hydrate formation in nanopores: A molecular dynamics study.

Hypothesis: Mixed clays (e.g. montmorillonite, illite and kaolinite) are ubiquitous in hydrate-bearing sediments under seafloor, and their surfaces inevitably affect the formation of natural gas hydrates therein.

Formation of CH Hydrate in a Mesoporous Metal-Organic Framework MIL-101: Mechanistic Insights from Microsecond Molecular Dynamics Simulations.

The formation of CH hydrate in a mesoporous metal-organic framework MIL-101 is investigated by microsecond molecular dynamics simulations. CH hydrate is observed to form preferentially in the outer space of MIL-101 cavities rather than inside the cavities; only when the hydrate formation is nearly complete in the outer space can stable hydrate form in MIL-101 cavities. The underlying reason is revealed to be the easy dissociation of small hydrate clusters formed in the nanospace of the cavities, because of the diffusion of CH molecules out of the cavities into the outer space.

Electric-Field Effects on Ionic Hydration: A Molecular Dynamics Study.

In this work, we report the electric-field effects on ionic hydration of Cl, Na, and Pb using molecular dynamics simulations. It is found that the effect of weak fields on ionic hydration can be neglected. Strong fields greatly disturb the water orientation in the hydration shells of ions, though ion coordination number remains almost unchanged.

CH Hydrate Formation between Silica and Graphite Surfaces: Insights from Microsecond Molecular Dynamics Simulations.

Microsecond simulations have been performed to investigate CH hydrate formation from gas/water two-phase systems between silica and graphite surfaces, respectively. The hydrophilic silica and hydrophobic graphite surfaces exhibit substantially different effects on CH hydrate formation. The graphite surface adsorbs CH molecules to form a nanobubble with a flat or negative curvature, resulting in a low aqueous CH concentration, and hydrate nucleation does not occur during 2.

What are the key factors governing the nucleation of CO hydrate?

Microsecond molecular dynamics simulations were performed to provide molecular insights into the nucleation of CO hydrate. The adsorption of sufficient CO molecules around CO hydration shells is revealed to be crucial to effectively stabilize the hydrogen bonds formed therein, catalyzing the hydration shells into hydrate cages and inducing the nucleation. Moreover, a high aqueous CO concentration is found to be another key factor governing the nucleation of CO hydrate, and only above a critical concentration can the nucleation of CO hydrate occur.

A mechanical nanogate based on a carbon nanotube for reversible control of ion conduction.

Control of mass transport through nanochannels is of critical importance in many nanoscale devices and nanofiltration membranes. The gates in biological channels, which control the transport of substances across cell membranes, can provide inspiration for this purpose. Gates in many biological channels are formed by a constriction ringed with hydrophobic residues which can prevent ion conduction even when they are not completely physically occluded.

Bioinspired graphene nanopores with voltage-tunable ion selectivity for Na(+) and K(+).

Biological protein channels have many remarkable properties such as gating, high permeability, and selectivity, which have motivated researchers to mimic their functions for practical applications. Herein, using molecular dynamics simulations, we design bioinspired nanopores in graphene sheets that can discriminate between Na(+) and K(+), two ions with very similar properties. The simulation results show that, under transmembrane voltage bias, a nanopore containing four carbonyl groups to mimic the selectivity filter of the KcsA K(+) channel preferentially conducts K(+) over Na(+).