scholarly journals Mass Transfer Through Graphene-Based Membranes

2020 ◽  
Vol 10 (2) ◽  
pp. 455
Author(s):  
Valerij Levdansky ◽  
Olina Šolcová ◽  
Karel Friess ◽  
Pavel Izák
Keyword(s):  
Mass Transfer ◽  
Graphene Oxide ◽  
Kinetic Parameters ◽  
Resonance Radiation ◽  
Experimental Results ◽  
Surface Processes ◽  
Graphene Sheets ◽  
External Fields ◽  
Nanoporous Graphene ◽  
Gas Molecules

The problems related to the transport of gases through nanoporous graphene (NG) and graphene oxide (GO) membranes are considered. The influence of surface processes on the transport of gas molecules through the aforementioned membranes is studied theoretically. The obtained regularities allow finding the dependence of the flux of the gas molecules passing through the membrane on the kinetic parameters which describe the interaction of the gas molecules with the graphene sheets. This allows to take into account the influence of external fields (e.g., resonance radiation), affecting the aforementioned kinetic parameters, on the transport of gas molecules through the membranes. The proposed approach makes it possible to explain some experimental results related to mass transfer in the GO membranes. The possibility of the management of mass transfer through the NG and GO membranes using resonance radiation is discussed.

Molecular Perspective of Radionuclides Separation by Nanoporous Graphene Oxide Membrane

2016 ◽  
Vol 11 (1) ◽  
pp. 3-5 ◽  
Author(s):  
Masoud Arabieh ◽  
S. Mahmood Fatemi ◽  
Hamid Sepehrian
Keyword(s):  
Graphene Oxide ◽  
Md Simulation ◽  
Oil Industry ◽  
Diffusion Flow ◽  
Nanoporous Graphene ◽  
Gas Molecules ◽  
Oxide Membrane ◽  
Oxide Membranes ◽  
Molecular Sieving ◽  
Graphene Oxide Membranes

Abstract Graphene-derived membranes has gained much interest recently due to its promising potential in filtration and separation applications. Molecular Sieving phenomena of gas molecules in the interlayer of graphene oxide nanopore have been investigated using molecular dynamic (MD) simulation. We explore I-129 gas radionuclides sequestration from natural air in nanoporous graphene oxide membranes in which different sizes and geometries of pores were modeled on the graphene oxide sheet. In the present work, mean-squared displacement (MSD), diffusion, flow of gas and the number of crossed gas molecules through graphene oxide nanopore membrane have been calculated and the results showed, selective proper nanopores in graphene oxide membrane could dramatically improve separation. The aim of this paper is to show that for the well-defined pore size called P-12, it is possible to separate I-129 from a gas mixture containing I-129, O2 and N2. The results would be benefited by the oil industry and others.

Interfacial mass transfer in turbulent flow accompanied by irreversible first order chemical reaction

1979 ◽  
Vol 44 (5) ◽  
pp. 1388-1396
Author(s):  
Václav Kolář ◽  
Zdeněk Brož
Keyword(s):  
Mass Transfer ◽  
Turbulent Flow ◽  
Chemical Reaction ◽  
Experimental Results ◽  
Theoretical Concepts ◽  
First Order ◽  
Order Chemical Reaction ◽  
Interfacial Mass Transfer ◽  
First Order Chemical Reaction

Relations describing the mass transfer accompanied by an irreversible first order chemical reaction are derived, based on the formerly published general theoretical concepts of interfacial mass transfer. These relations are compared with experimental results taken from literature.

scholarly journals Diamine vapor treatment of viscoelastic graphene oxide liquid crystal for gas barrier coating

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seung Eun Choi ◽  
Sung-Soo Kim ◽  
Eunji Choi ◽  
Ji Hoon Kim ◽  
Yunkyu Choi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Liquid Crystal ◽  
Diffusion Length ◽  
Barrier Properties ◽  
Gas Barrier ◽  
Barrier Coating ◽  
Coating Method ◽  
Gas Molecules ◽  
Pet Film ◽  
Vapor Treatment

AbstractA layered graphene oxide/ethylenediamine (GO/EDA) composite film was developed by exposing aqueous GO liquid crystal (GOLC) coating to EDA vapor and its effects on the gas barrier performance of GO film were systematically investigated. When a GO/EDA coating with a thickness of approximately 1 μm was applied to a neat polyethylene terephthalate (PET) film, the resultant film was highly impermeable to gas molecules, particularly reducing the gas permeance up to 99.6% for He and 98.5% for H2 in comparison to the neat PET film. The gas barrier properties can be attributed to the long diffusion length through stacked GO nanosheets. The EDA can crosslink oxygen-containing groups of GO, enhancing the mechanical properties of the GO/EDA coating with hardness and elastic modulus values up to 1.14 and 28.7 GPa, respectively. By the synergistic effect of the viscoelastic properties of GOLC and the volatility of EDA, this coating method can be applied to complex geometries and EDA intercalation can be spontaneously achieved through the scaffold of the GOLC.

Structural and vibrational study of graphene oxide via coronene based models: theoretical and experimental results

2016 ◽  
Vol 3 (5) ◽  
pp. 055020 ◽  
Author(s):  
João Paulo Almeida de Mendonça ◽  
Alessandro Henrique de Lima ◽  
Georgia Maria Amaral Junqueira ◽  
Welber Gianini Quirino ◽  
Cristiano Legnani ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Experimental Results ◽  
Vibrational Study

scholarly journals Thermal Steady States of Gases in a Gravitational Field

2011 ◽  
Vol 66 (1-2) ◽  
pp. 123-133
Author(s):  
Kunihiko Kigoshi
Keyword(s):  
Heat Transfer ◽  
Gravitational Field ◽  
Temperature Difference ◽  
Thermal Gradient ◽  
Vertical Direction ◽  
Steady States ◽  
Gas Pressure ◽  
Experimental Results ◽  
Gravity Effect ◽  
Gas Molecules

This paper presents results on observations of a temperature difference between the top and bottom of a vessel filled with gas in a gravitational field. The observed temperature at the top of the vessel was always lower than the temperature at the bottom of the vessel, and this temperature difference was persistent and steady over more than 20 h. The magnitude of the temperature difference depends on the types of gas molecules present but is independent of the gas pressure in the vessel within the range from 2.7×104 Pa to 27 Pa. A temperature difference between the top and the bottom is only observed along the vertical direction and is only observed when the vessel contains a gas. These experimental results indicate a gravity effect on molecular heat transfer which enables the transport of energy in the gas without a thermal gradient.

scholarly journals Processes of heat and mass transfer during drying of red beetroot

2020 ◽  
Vol 6 (2) ◽  
pp. 81-87
Author(s):  
Zhanna Petrova ◽  
◽  
Kateryna Samoilenko ◽  
Vitaly Vishnevsky
Keyword(s):  
Mass Transfer ◽  
Energy Consumption ◽  
Heat And Mass Transfer ◽  
Raw Materials ◽  
Antioxidant Properties ◽  
Calculation Model ◽  
Experimental Results ◽  
Biologically Active ◽  
Raw Material ◽  
Drying Process

Red beetroot is the main raw material which has a high content of betanine with antioxidant properties. An important emphasis in the processing of antioxidant raw materials by drying is to reduce energy consumption for the dehydration process, the maximum preservation of biologically active substances, and to reduce the cost of the final product. Drying is a complex and energy-intensive process. Therefore, to optimize energy consumption during drying and selection of rational modes of dehydration, it is necessary to apply the calculated analysis of heat and mass transfer on the basis of adequate mathematical models. Calculated and experimental results are compared. In general, the comparison of the results of numerical modeling of convection drying processes of the red beetroot sample with the experimental results showed their rather satisfactory qualitative agreement. The calculation model can be used to approximate the characteristics of the drying process of red beetroot, in particular the time required for drying. The obtained results of calorimetric studies allow stating that with correctly selected compositions, not only the components of native raw materials are stabilized, but also the drying process is intensified with the reduction of energy consumption to process.

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