Single-layer membranes for organic solvent nanofiltration: a molecular dynamics simulation and comparative...

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Organic solvents are crucial in pharmaceutical and chemical industries, but their separation and recovery are energy-intensive and costly.
• Developing efficient membranes for organic solvent nanofiltration (OSN) is vital for sustainable industrial processes.

Purpose of the Study:

• To investigate molybdenum disulfide (MoS₂) membranes with varying pore sizes and chemistries for OSN applications.
• To predict and analyze the flux of various organic solvents through MoS₂ membranes using molecular simulation.
• To evaluate the performance of MoS₂ membranes in separating organic solvents and solutes.

Main Methods:

• Molecular simulation was employed to study MoS₂ membranes with pore sizes ranging from 0.6 nm to 1.4 nm.
• The potential of mean force (PMF) was calculated to understand solvent-membrane interactions and energy barriers.
• Experimental validation was conducted to compare simulated solvent permeability with real-world performance.

Main Results:

• MoS₂ membranes exhibited selective solvent transport, with smaller pores (0.6 nm S pore) showing better flux for certain solvents than larger ones (0.7 nm Mo pore).
• Polar solvents encountered higher energy barriers within the MoS₂ pores, indicating selective resistance.
• Simulated and experimental results showed consistent trends in solvent flux changes.
• MoS₂ membranes achieved 100% rejection of acetaminophen, with minimal impact on solvent permeability.

Conclusions:

• Both pore size and pore chemistry are critical factors in the performance of MoS₂ membranes for OSN.
• MoS₂ is a highly promising material for developing efficient membranes for organic solvent recovery in industrial applications.