This Methods Collection focuses on high internal phase emulsions (HIPEs)—specifically their formulation, interfacial properties, templating strategies, characterization, and applications. Compared to conventional emulsions, HIPEs exhibit unique features such as high emulsion stability, viscoelastic behavior, and—as the name suggests—a very high internal phase volume. These characteristics, individually or in combination, make HIPEs attractive for use in food science and drug delivery due to their excellent stability and encapsulation efficiency, as well as in 3D printing applications where they can function as printable inks.

Moreover, solidification of the continuous phase followed by removal of the internal phase yields highly porous materials in the form of monoliths, thin films, or microspheres. By tuning the HIPE formulation or the solidification process, one can generate materials with either highly interconnected or closed-cell porous morphologies. These morphologies support diverse applications: interconnected structures are widely used in tissue engineering scaffolds, catalyst supports, and absorbents, while closed-cell architectures are preferred in encapsulation systems, such as thermal energy storage.

While HIPEs and their derived templates offer significant versatility, achieving optimal performance requires careful tuning of preparation and processing parameters. This collection aims to provide researchers with robust, visualized methods to harness the full potential of HIPE-based systems across disciplines, including materials science, soft matter, food science, and applied engineering.