Zeolitic Imidazolate Framework Membranes for Organic Solvent Nanofiltration: A Molecular Simulation Exploration

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Organic solvents are crucial in chemical and pharmaceutical industries.
• Solvent separation and recovery are energy-intensive and costly processes.
• Developing efficient membranes for organic solvent nanofiltration (OSN) is essential.

Purpose of the Study:

• To investigate zeolitic imidazolate frameworks (ZIF-25, ZIF-71, ZIF-96) as potential OSN membranes.
• To predict solvent fluxes through these ZIF membranes using molecular simulations.
• To understand the role of pore chemistry and solvent-framework interactions in permeation.

Main Methods:

• Molecular simulations were employed to study three ZIFs (ZIF-25, ZIF-71, ZIF-96).
• Solvent fluxes for methanol, ethanol, acetone, acetonitrile, and n-hexane were predicted.
• Analysis included structural information, interaction energy, and solvent properties.

Main Results:

• ZIF-25, despite small pores, showed high flux for polar solvents due to hydrophobicity.
• ZIF-96 demonstrated high flux for nonpolar n-hexane due to hydrophilicity.
• Solvent permeance strongly correlated with solvent-framework interactions and properties.
• Paracetamol rejection was 100% for all ZIFs across tested solvents.

Conclusions:

• Pore chemistry significantly influences solvent permeation in OSN membranes.
• ZIFs exhibit potential as effective membranes for organic solvent recovery.
• The findings guide the design of advanced membranes for industrial separation processes.