Ultrathin Subnanoporous Covalent Organic Framework Membranes with Triangular Topologies for Efficient Pharmaceutical...

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Covalent organic frameworks (COFs) offer tunable pore structures for pharmaceutical separation via organic solvent nanofiltration (OSN).
• Developing robust COF membranes with precise nanochannels for efficient separation remains a significant challenge in the field.

Purpose of the Study:

• To design and synthesize a novel triangular-topology COF membrane with subnanometer pores for high-performance OSN.
• To evaluate the membrane's efficiency in separating mixed antitumor pharmaceuticals in organic solvents.

Main Methods:

• A six-fold symmetric hexa(4-formylphenyl)benzene building block was used to create a triangular-topology COF.
• Interfacial synthesis of a dense COF membrane on porous substrates via sustained diffusion and reaction of hydrazine.
• Characterization of membrane properties including thickness, pore size, and solvent affinity.

Main Results:

• The synthesized COF membrane has an ultrathin thickness (54 nm) with high-density nanochannels and excellent solvent affinity.
• Achieved exceptional solvent permeances (e.g., 24.9 L m⁻¹ h⁻¹ bar⁻¹ for methanol) and sharp molecular rejections (380 Da MWCO).
• Demonstrated superior separation of mixed antitumor pharmaceuticals in organic solvents under demanding conditions.

Conclusions:

• The developed COF membrane exhibits outstanding performance, outperforming existing OSN membranes.
• This advanced COF membrane design shows significant promise for industrial separation of high-value pharmaceuticals.
• The study highlights the potential of COF membranes in revolutionizing pharmaceutical separation processes.