Engineering Protein-Based Nanofiltration Membranes with Sub-Nanometer Pores via Amyloid-Like Aggregation

Area of Science:

• Materials Science
• Biomimetic Engineering
• Nanotechnology

Background:

• Biological membrane proteins excel at selective molecular transport via sub-nanometer channels.
• Artificial protein membranes struggle with precise sub-nanometer pore size control, limiting selectivity.
• Developing artificial membranes with biomimetic precision is crucial for advanced separation technologies.

Purpose of the Study:

• To fabricate proteinaceous nanofiltration membranes with precisely defined sub-nanometer pores.
• To enhance ion sieving performance and surface properties through crosslinking.
• To demonstrate the potential for water purification, ion separation, and environmental remediation.

Main Methods:

• Formation of a protein membrane at the air/water interface using thiol-disulfide exchange reactions.
• Subsequent crosslinking with polyphenol to reduce pore size and alter surface charge.
• Performance evaluation using MgCl2 rejection, Mg2+/Li+ selectivity in simulated brine, and stability tests.

Main Results:

• Fabricated membranes with initial pore sizes of 0.62-0.81 nm, reduced to ~0.4 nm after polyphenol crosslinking.
• Achieved 98.24% MgCl2 rejection and 88.65 Mg2+/Li+ selectivity, outperforming many polymer membranes.
• Demonstrated excellent chemical stability, anti-fouling properties, and versatility in separating various contaminants.

Conclusions:

• The developed protein membrane offers precise sub-nanometer pore control, mimicking biological channels.
• Polyphenol crosslinking significantly enhances ion selectivity and membrane stability.
• This biomimetic approach presents a paradigm shift for next-generation separation and remediation technologies.