Efficient separation of He/CH₄ mixture by functionalized graphenylene membranes: A theoretical study.

Area of Science:

• Materials Science
• Chemical Engineering
• Computational Chemistry

Background:

• Graphenylene membranes offer potential for gas separation.
• Functionalization is key to enhancing membrane performance.
• Efficient helium separation is crucial for various industrial applications.

Purpose of the Study:

• To investigate the He/CH4 separation performance of functionalized graphenylene membranes.
• To compare the separation capabilities of pristine versus functionalized graphenylene.
• To understand the molecular mechanisms governing gas transport and separation.

Main Methods:

• Molecular dynamics (MD) simulations were employed.
• Gas molecule transport through membranes was monitored.
• Van der Waals (vdW) interactions and potential of mean force (PMF) calculations were performed.

Main Results:

• Methane molecules were blocked, while helium molecules permeated the functionalized membranes.
• Ultrahigh selectivity for helium over methane was demonstrated.
• Maximum helium permeance reached approximately 1 x 10^7 GPU at room temperature.
• Methane adsorption on the membrane surface was observed, but helium diffusion was favored through nanopores.

Conclusions:

• Functionalized graphenylene membranes provide both high permeance and selectivity for helium separation.
• These membranes are a promising candidate for highly efficient helium purification systems.
• Understanding gas-membrane interactions is crucial for optimizing separation performance.