Molecular dynamics studies on zeolites. II: A simple model for silicates applied to anhydrous natrolite

Demontis, Pierfranco; Suffritti, Giuseppe Baldovino; Quartieri, Simona; Fois, Ettore; Gamba, Aldo

doi:10.1016/0144-2449(87)90091-1

Cited by 75 publications

(61 citation statements)

References 9 publications

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“…In Fig. 18 we show the self-diffusivity of ethane using the Lennard-Jones ͑LJ͒ parameters of Table II and compare the results of a rigid zeolite to the flexible model of Demontis et al 60,61 Error bars are smaller or comparable to the symbol size. We have added the results of Schüring et al 43 for the infinite dilution case, and for 1 molecule"cage.…”

Section: Discussionmentioning

confidence: 99%

Molecular simulation of loading-dependent diffusion in nanoporous materials using extended dynamically corrected transition state theory

Dubbeldam

Beerdsen

Vlugt

et al. 2005

The Journal of Chemical Physics

143

210

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A dynamically corrected transition state theory method is presented that is capable of computing quantitatively the self-diffusivity of adsorbed molecules in confined systems at nonzero loading. This extention to traditional transition state theory is free of additional assumptions and yields a diffusivity identical to that obtained by conventional molecular-dynamics simulations. While molecular-dynamics calculations are limited to relatively fast diffusing molecules, our approach extends the range of accessible time scales significantly beyond currently available methods. We show results for methane, ethane, and propane in LTL-and LTA-type zeolites over a wide range of temperatures and loadings, and demonstrate the extensibility of the method to mixtures.

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Section: Discussionmentioning

confidence: 99%

Molecular simulation of loading-dependent diffusion in nanoporous materials using extended dynamically corrected transition state theory

Dubbeldam

Beerdsen

Vlugt

et al. 2005

The Journal of Chemical Physics

143

210

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“…These data indicate that flexible lattices can enhance the diffusion coefficient by 6-39%. Most of the studies used the model proposed by Demontis et al, 13,14 as this is a very efficient model for introducing lattice flexibility. However, Leroy et al 12 studied the influence of the flexibility model chosen and observed that, for methane in silicalite, there is a substantial impact of how flexibility is modeled.…”

Section: Introductionmentioning

confidence: 99%

In-Depth Study of the Influence of Host−Framework Flexibility on the Diffusion of Small Gas Molecules in One-Dimensional Zeolitic Pore Systems

et al. 2007

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Molecular-dynamics simulations are performed to understand the role of host-framework flexibility on the diffusion of methane molecules in the one-dimensional pores of AFI-, LTL-, and MTW-type zeolites. In particular, the impact of the choice of the host model is studied. Dynamically corrected Transition State Theory is used to provide insights into the diffusion mechanism on a molecular level. Free-energy barriers and dynamical correction factors can change significantly by introducing lattice flexibility. In order to understand the phenomenon of free-energy barriers reduction, we investigate the motion of the window atoms. The influence that host-framework flexibility exerts on gas diffusion in zeolites is, generally, a complex function of material, host model, and loading such that transferability of conclusions from one zeolite to the other is not guaranteed.

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“…For example, Demontis and co-workers reported the positions and vibrations of water molecules in the cages of natrolite [20,21], the atomic coordinates and the crystal symmetry of dehydrated natrolite [22] and Linde zeolite 4A [23], the diffusive motion of methane in silicate [24] and the structural changes of silicate at different temper atures [25]. Cohen de Lara and co-workers also performed an MD study of methane adsorbed in zeolite-A [26] based on their potential-energy calcula tion [27].…”

Section: Introductionmentioning

confidence: 99%

Molecular Dynamics Study on the Adsorption Selectivity for Negative Elements in Aluminosilicates

Matsumiya¹,

Takagi

2001

Zeitschrift Für Naturforschung A

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For the pyrochemical reprocessing o f spent metallic nuclear fuels in molten salt baths it is important to investigate the adsorption selectivity o f cations in aluminosilicates. A molecular dynamics simulation has been performed on sodalite and zeolite with exchangeable monovalent and multivalent cationic fission products at 673 K in order to calculate their self-diffusion coefficients in the aluminosilicate framework and estimate the selectivity o f the exchangeable cations. The results enables us to conclude that the self-diffusion coefficients of monovalent cations decrease with increasing ionic radius. The order of the adsorption selectivity is Li < K < Na < Cs in sodalite and Li < Na < K < Cs in zeolite. The self-diffusion coefficients of multivalent cations are almost independent o f the ionic radius, and these cations are in aluminosilicates more stable than monovalent cations. The results are consistent with the experimental results.

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Molecular dynamics studies on zeolites. II: A simple model for silicates applied to anhydrous natrolite

Cited by 75 publications

References 9 publications

Molecular simulation of loading-dependent diffusion in nanoporous materials using extended dynamically corrected transition state theory

Molecular simulation of loading-dependent diffusion in nanoporous materials using extended dynamically corrected transition state theory

In-Depth Study of the Influence of Host−Framework Flexibility on the Diffusion of Small Gas Molecules in One-Dimensional Zeolitic Pore Systems

Molecular Dynamics Study on the Adsorption Selectivity for Negative Elements in Aluminosilicates

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