Distinct Understanding of Constant-Volume/Variable-Pressure Experimental Method on CO2 Capture Using Graphtriyne Membrane through an Atomistic Approach

A Khorsandi-Langol and SM Hashemianzadeh, JOURNAL OF PHYSICAL CHEMISTRY C, 123, 15523-15533 (2019).

DOI: 10.1021/acs.jpcc.9b01988

In this research, the nonequilibrium thermodynamics of the gas permeation process based on the constant-volume/variable-pressure experimental method was explored with the novel algorithm using atomistic simulation. The hybrid force field and the in-house FORTRAN code were used in the proposed algorithm and the pressure was considered through the exerted spring force within the NVT ensemble. The graphtriyne layers were utilized as a porous membrane for the investigation of N-2 and CO2 permeation. Two parameters of free tendency and channel cross-sectional area (CCSA) were introduced to analyze the result of the simulation. The result of the simulation revealed that the effect of the CCSA on N-2 permeation decreases as the number of graphtriyne layers increases, whereas the CO2 permeation through the membrane is independent of the CCSA. Also, there is a distinct permeation behavior for CO2 and N-2 so that first CO2 is trapped within the graphtriyne layers and then permeation is started. In contrast, trapping of N-2 increases with increasing the number of graphtriyne layers in the permeation process. This trend originated from the higher free tendency of CO2 relative to N-2, which is confirmed by the time- dependent density parameter. Hence, it is possible to make the membrane permselective by adjusting the pressure and number of graphtriyne layers.

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