Roll-to-Roll Fabrication of Bijels via Solvent Transfer Induced Phase Separation (R2R-STrIPS)

Bicontinuous interfacially jammed emulsion gels (bijels) are soft materials with applications in separation science, energy storage, catalysis, and tissue engineering. Bijels are formed by arresting the liquid–liquid phase separation of two immiscible liquids via interfacial jamming of colloidal particles. Current fabrication methods of bijels employ either batch processing or continuous-flow microfluidic synthesis. Production methods with higher throughput are needed to facilitate large-scale synthesis of bijels. Herein, it is shown that roll-to-roll processing (R2R) enables the fabrication of bijel films with controlled dimensions at rates of several cm³ per minute. Increasing the bijel production rate via R2R requires an understanding of the interaction of the bijel with the R2R substrate. The study demonstrates that controlling the wetting on the R2R substrate enables the synthesis of uniform bijel films with adjustable thickness. Moreover, this research shows that the bijel film microstructure depends on the mechanism of phase separation and particle surface functionalization. The resulting knowledge gains can help to leverage bijel synthesis from laboratory to industrial scales in the future, promoting the exciting application potentials of bijels.