Analysis of bijel formation dynamics during solvent transfer-induced phase separation using phase-field simulations

Area of Science:

• Soft Matter Physics
• Materials Science
• Chemical Engineering

Background:

• Solvent transfer-induced phase separation (STrIPS) fabricates bicontinuous interfacially jammed emulsion gels (bijels).
• Bijels have potential applications in membrane separation and energy storage.
• Current STrIPS methods lack in situ observation, hindering understanding of bijel formation.

Purpose of the Study:

• To develop a phase-field (PF) model for STrIPS to enable in situ observation of bijel formation.
• To correlate the phase separation process with the resulting bijel morphology.
• To elucidate the mechanisms governing bijel structure formation in STrIPS.

Main Methods:

• Development of a phase-field (PF) model simulating STrIPS.
• Comparison of model predictions with experimental results.
• Analysis of phase separation dynamics and solvent diffusion within the model.

Main Results:

• The PF model accurately reproduces experimental STrIPS morphological trends.
• The model reveals that slow phase separation dynamics relative to solvent diffusion influence bijel structure.
• In situ visualization of phase separation during the STrIPS process was achieved.

Conclusions:

• The PF model provides crucial insights into STrIPS bijel formation mechanisms.
• This modeling approach can guide the fabrication of novel bijel morphologies.
• Understanding formation dynamics is key to optimizing bijel properties for applications.