Molecular dynamics study of sorbate diffusion in a simple porous membrane containing microporous nanocrystals and mesopores

Knauth, Markus; Vasenkov, Sergey; Kärger, Jörg; Fritzsche, Siegfried

doi:10.1016/j.cplett.2009.07.106

Cited by 6 publications

(2 citation statements)

References 24 publications

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“…Zeolites are crystalline aluminosilicates built from TO 4 tetrahedra (T = Si and Al) with excellent properties of high surface area, uniform and precise microporosity, shape selectivity, high ion-exchange capacity, strong Brønsted acidity and high thermal and hydrothermal stability [ 1 ]. Therefore, zeolites have been widely used in many environmental and other industrial applications, such as ion exchange [ 2 , 3 , 4 , 5 ], catalysts [ 6 , 7 , 8 , 9 ], membrane separations [ 10 , 11 , 12 ] and adsorbents [ 13 , 14 , 15 , 16 , 17 ].…”

Section: Introductionmentioning

confidence: 99%

One-Step Hydrothermal Synthesis of Zeolite X Powder from Natural Low-Grade Diatomite

et al. 2018

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Zeolite X powder was synthesized using natural low-grade diatomite as the main source of Si but only as a partial source of Al via a simple and green hydrothermal method. The microstructure and surface properties of the obtained samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), wavelength dispersive X-ray fluorescence (XRF), calcium ion exchange capacity (CEC), thermogravimetric-differential thermal (TG-DTA) analysis, and N2 adsorption-desorption technique. The influence of various synthesis factors, including aging time and temperature, crystallization time and temperature, Na2O/SiO2 and H2O/Na2O ratio on the CEC of zeolite, were systematically investigated. The as-synthesized zeolite X with binary meso-microporous structure possessed remarkable thermal stability, high calcium ion exchange capacity of 248 mg/g and large surface area of 453 m2/g. In addition, the calcium ion exchange capacity of zeolite X was found to be mainly determined by the crystallization degree. In conclusion, the synthesized zeolite X using diatomite as a cost-effective raw material in this study has great potential for industrial application such as catalyst support and adsorbent.

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Section: Introductionmentioning

confidence: 99%

One-Step Hydrothermal Synthesis of Zeolite X Powder from Natural Low-Grade Diatomite

et al. 2018

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“…A number of studies have used computer simulations to study diffusion in structured porous membranes including zeolites, − carbon nanotubes − and mesoporous silicas. − In this paper, we present the results of binary diffusion simulations in a series of functionalized MCM-41 pores. The outline of the paper is as follows: In the next section, we outline the EF-NEMD method used for the calculation of the transport properties.…”

Section: Introductionmentioning

confidence: 99%

Influence of Surface Groups on the Diffusion of Gases in MCM-41: A Molecular Dynamics Study

2011

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The diffusion of binary mixtures of CO2 and N2 in a series of functionalized MCM-41 materials was studied using molecular dynamics (MD) simulations. Transport diffusion coefficients were obtained in order to assess the effect of surface functionalization with organic groups. Unmodified MCM-41 was found to be transport selective for N2. The spatial distribution of the two coadsorbed species showed that N2 molecules permeated faster and occupied the central pore region to a greater extent than CO2 molecules. CO2 was found to have a much lower permeability than N2 due to stronger interactions with the surface of MCM-41 and a tendency to become trapped in nooks in the amorphous pore wall. This effect was not reproduced when using a more simplistic model pore with a smooth surface demonstrating the importance of using a realistic pore model. Larger aminophenyl surface groups were found to significantly reduce the N2 selectivity due to a decrease in the flux of N2 and an increase in the flux of CO2. We explain this effect in terms of the marked difference in the transport mechanisms of CO2 and N2 in functionalized MCM-41 materials. Lastly, we remark on the importance of calculating the cross-term diffusion coefficients for this series of materials.

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Experimental and molecular dynamics study of gas flow characteristics in nanopores

Liu

Jiang

2012

Chin. Sci. Bull.

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Gas flow characteristics in nanopores were investigated experimentally and numerically using molecular dynamics (MD) simulations with an emphasis on the friction factor and gas viscosity. The results show that the viscosity and the friction factor in nanopores are much lower than those in macroscale channels. The actual viscosities obtained from the MD studies showed that the gas viscosity in nanopores is less than the macroscale viscosity because collisions between gas molecules are less frequent in high Knudsen number flows and there are more collisions with the wall. The MD simulations show that the velocity profile is composed of two parts, with a much steeper velocity gradient near the wall. gas flow, nanopore, friction factor, molecular dynamics simulation Citation:Liu Q X, Jiang P X, Xiang H. Experimental and molecular dynamics study of gas flow characteristics in nanopores.

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Molecular dynamics study of sorbate diffusion in a simple porous membrane containing microporous nanocrystals and mesopores

Cited by 6 publications

References 24 publications

One-Step Hydrothermal Synthesis of Zeolite X Powder from Natural Low-Grade Diatomite

One-Step Hydrothermal Synthesis of Zeolite X Powder from Natural Low-Grade Diatomite

Influence of Surface Groups on the Diffusion of Gases in MCM-41: A Molecular Dynamics Study

Experimental and molecular dynamics study of gas flow characteristics in nanopores

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