Tuning the Pore Size in Gradient Poly(ionic liquid) Membranes by Small Organic Acids

Area of Science:

• Materials Science
• Polymer Chemistry
• Membrane Technology

Background:

• Developing advanced porous membranes with controlled structures is crucial for separation processes.
• Existing methods often lack precise control over pore size and gradient formation.

Purpose of the Study:

• To develop highly charged porous polymer membranes with adjustable pore size and gradient structures.
• To investigate the mechanism of ammonia-triggered electrostatic complexation for membrane fabrication.

Main Methods:

• Fabrication of membranes via electrostatic complexation between a poly(ionic liquid) (PIL) and multivalent benzoic acid derivatives.
• Utilizing ammonia diffusion to induce gradient pore structure and in situ cross-linking.
• Characterization of membrane properties based on varying fabrication parameters.

Main Results:

• Successfully prepared highly charged porous polymer membranes with tunable pore size and gradient pore structure.
• Demonstrated control over pore characteristics by adjusting acid multivalency, PIL/carboxylate ratio, and PIL counteranion.
• Ammonia-triggered electrostatic complexation effectively fixed the gradient pore structure.

Conclusions:

• The developed method provides a versatile route to engineer porous polymer membranes with tailored properties.
• This approach enables precise control over membrane architecture for advanced separation applications.