Understanding ultrafast free-rising bubble capturing on nano/micro-structured super-aerophilic surfaces

Abstract

Rapid bubble capture is essential for collecting targeted gaseous media and eliminating floating impurities across aquatic environments. While the role of nanostructures during the collision of free-rising bubbles with super-aerophilic surfaces is well established, the fundamental contribution of microtextures in promoting initial capture, even before contact, has yet to be fully understood. We report the rising bubble-induced large deformation of the entrapped gas layer, rapidly thinning the liquid film to its rupture threshold and thus achieving an ultrafast bubble capture down to about 1 ms with an array of microcones, decorated with nanoparticles as a convenient example to obtain super-aerophilicity. This rapid capture is also very stable due to the hysteresis movement of three-phase contact lines that inspired a critical pressure criterion for ensuring gas-layer stability and capture efficacy. The present nano/microstructured surface supports prolonged, loss-free gas transport in challenging shear flow as well, providing robust bubble control strategies for diverse systems.