scholarly journals Prediction of Adsorption and Diffusion Behaviors of CO2 and CH4 in All-Silica Zeolites Using Molecular Simulation

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 392
Author(s):  
Yasuhisa Hasegawa ◽  
Chie Abe
Keyword(s):  
Material Properties ◽  
High Accuracy ◽  
Dynamics Simulation ◽  
Membrane Material ◽  
Promising Technique ◽  
Zeolite Structure ◽  
Bonding Interaction ◽  
Type Zeolite ◽  
And Diffusion ◽  
Diffusion Behaviors

Computational chemistry is a promising technique for the prediction of material properties. Adsorption and diffusion behaviors in zeolite micropores are important for zeolite membranes. In this study, we investigated novel non-bonding interaction parameters of all-silica zeolites for the prediction of the adsorption and diffusion behaviors by focusing on the Si atom of zeolite frameworks. Our parameters (σ = 0.421 nm, ε = 0.954 kJ mol−1, and q = +1.10 e) were close to theoretically derived values, and the adsorption isotherms of CO2 and CH4 on several zeolites could be predicted with high accuracy. Furthermore, the parameters gave the suitable self-diffusivities of CO2 and CH4 within MFI-type zeolite micropores through molecular dynamics simulation. Those suggest that our derived parameters are useful for selecting zeolite structure as the membrane material.

scholarly journals Molecular Dynamics Simulation of Distribution and Diffusion Behaviour of Oil–Water Interfaces

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1905 ◽  
Author(s):  
Chengbin Zhang ◽  
Hanhui Dai ◽  
Pengfei Lu ◽  
Liangyu Wu ◽  
Bo Zhou ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Interface Roughness ◽  
Dynamics Simulation ◽  
Water Phase ◽  
Water Molecules ◽  
Water Interface ◽  
Oil Water ◽  
And Diffusion ◽  
Diffusion Behaviors

The distribution and diffusion behaviors of microscopic particles at fluorobenzene–water and pentanol–water interfaces are investigated using molecular dynamics simulation. The influences of Na+/Cl− ions and the steric effects of organic molecules are examined. The concentration distributions of different species, the orientations of oil molecules at the interface, and oil–water interface morphology as well as the diffusion behaviors of water molecules are explored and analyzed. The results indicate that a few fluorobenzene molecules move into the water phase influenced by Na+/Cl− ions, while the pentanol molecules at the interface prefer orientating their hydrophilic groups toward the water phase due to their large size. The water molecules more easily burst into the pentanol phase with larger molecular spaces. As the concentration of ions in the water phase increases, more water molecules enter into the pentanol molecules, leading to larger interface roughness and interface thickness. In addition, a lower diffusion coefficient for water molecules at the fluorobenzene–water interface are observed when introducing Na+/Cl− ions in the water phase, while for the pentanol–water system, the mobility of interfacial water molecules are enhanced with less ions and inhibited with more ions.

Solid-State Reaction and Diffusion Behaviors of CaFe2O4 and TiO2 at 1373 K to 1473 K

2021 ◽  
Author(s):  
Mingrui Yang ◽  
Junyi Xiang ◽  
Chenguang Bai ◽  
Xuangeng Zhou ◽  
Zhongci Liu ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
And Diffusion ◽  
Diffusion Behaviors ◽  
Reaction And Diffusion

Influences of Surface Substitutional Ti Atom on Hydrogen Adsorption, Dissociation, and Diffusion Behaviors on the α-U(001) Surface

2014 ◽  
Vol 118 (46) ◽  
pp. 26634-26640 ◽  
Author(s):  
Peng Shi ◽  
Yu Yang ◽  
Bingyun Ao ◽  
Ping Zhang ◽  
Xiaolin Wang
Keyword(s):  
Hydrogen Adsorption ◽  
And Diffusion ◽  
Diffusion Behaviors

Molecular dynamics simulation for structural heterogeneity and diffusion process in liquid GeO2

2021 ◽  
Vol 66 (1) ◽  
pp. 42-48
Author(s):  
Kien Pham Huu ◽  
Linh Nguyen Hong ◽  
Hien Pham Xuan ◽  
Linh Nguyen Thi Thuy ◽  
Quang Phan Dinh ◽  
...  
Keyword(s):  
Diffusion Process ◽  
Length Distribution ◽  
Structural Heterogeneity ◽  
Dynamics Simulation ◽  
Angle Distribution ◽  
Structural Units ◽  
Oxide Systems ◽  
Dynamical Heterogeneity ◽  
Liquid Oxide ◽  
And Diffusion

In this paper, we perform a simulation about liquid GeO2. The structure and diffusion process are analyzed through the radial distribution function, the distribution of GeOx (x = 4, 5, 6) structural units, length distribution, angle distribution, and data visualization. Simulation results show that the structure of liquid GeO2 composes clusters of GeO4, GeO5, or GeO6. These clusters have sizes depending on pressure and are distributed heterogeneously in space. This result confirms the origin of dynamical heterogeneity in the liquid oxide systems. In addition, the diffusion coefficient of Ge and O decreases upon pressure. We show that the diffusion relates to the breaking bond Ge-O.

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