Bioinspired Alveolar Sac-Like Hierarchical Foams Stabilized by Hydrophobic Copolymer Colloidal Particles

Hierarchical Pickering foams, which offer multifunctional integration through the synergistic action of multiscale bubbles, have attracted considerable research interest. The controllable fabrication and application-driven development of well-defined hierarchical foams have therefore become a prominent frontier in liquid foam research. Herein, we report a facile high-speed homogenization strategy to construct hierarchical Pickering foams with a unique alveolar sac-like architecture. These foams are stabilized by bubbles coated with hydrophobic random copolymer colloidal particles, while the formation process has turned out to be closely correlated with the hydrophobicity, composition, particle size, and zeta potential of the particles, as well as the surface tension, pH value, and salt concentration of the solution. Such a distinctive alveolar sac-like hierarchical structure comprises interconnected large bubble cavities surrounded by small bubbles, providing a well-defined multiscale platform for exploring interbubble interactions.