Understanding ultrafast free-rising bubble capturing on nano/micro-structured super-aerophilic surfaces
Yue Hu, Zhenbo Xu, Huanyu Shi, Benlong Wang, Liqiu Wang, Luwen Zhang
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.