Continuous production of multifunctional porous materials via photo-crosslinking of ice templated emulsions

Ice templating that uses water as a green porogen has emerged as an eco-friendly and promising approach to fabricating porous materials. However, foams prepared from aqueous solutions are typically water-intolerant owing to their hydrophilic nature. Hydrophobic foams can also be prepared through the freezing of dispersions, but extra organic solvents are often required, making it environmentally unfriendly. Herein, we develop photo-cross-linking of ice templated emulsions to produce multifunctional porous materials based on emulsifier-free photosensitive emulsions. The whole porogenation process is relatively fast (within several minutes) without freeze-drying, facilitating the roll-to-roll continuous production of porous polymers. The material versatility can be expanded with different formulations, including soft foams with high stretchability, rigid materials providing tunable shape memory properties, and hierarchical porous ceramics enabling thermal insulation. This approach is environmentally friendly and economically attractive, and the principle can be extended to diverse precursors for the production of functionalized porous materials.