Layer-by-layer Assembled Membranes with Immobilized Porins

Area of Science:

• Membrane science and technology
• Biomimetic materials
• Separation processes

Background:

• Advancements in membrane technology involve integrating bio-based channels for enhanced functionality.
• Outer membrane protein F (OmpF) trimers from Escherichia coli offer precise pore structures for selective transport.

Purpose of the Study:

• To develop and characterize OmpF-integrated membranes for selective separation of organic and ionic solutes.
• To evaluate the performance, stability, and pH responsiveness of these novel biomimetic membranes.

Main Methods:

• Layer-by-layer (LbL) assembly of OmpF trimers onto poly(vinylidene fluoride) microfiltration membranes.
• Characterization using fluorescence labeling (FITC), zeta potential measurements, and flux/rejection analyses.
• Testing of organic-inorganic solutions under continuous operation for over 160 hours.

Main Results:

• OmpF-membranes demonstrated selective rejection of non-charged organics (84% for 0.4-1.0 kDa) over ionic solutes.
• Achieved salt passage up to 2 times higher than traditional nanofiltration membranes.
• Exhibited pH-dependent salt rejection via Donnan exclusion and exceptional operational stability (>160 h).

Conclusions:

• OmpF-integrated membranes represent a significant advancement in biomimetic separation technology.
• These membranes offer a promising platform for efficient and stable selective separations with tunable properties.