Reliable manipulation of gas bubbles by regulating interfacial morphologies and chemical components

Abstract

The manipulation of gas bubble behavior is crucial to gas bubble-related applications. In nature, many biological surfaces offer reliable and effective manipulation of gas bubbles in aqueous media via unusual micro/nano-hierarchical structures and chemical compositions. This inspired us to construct a series of interfaces with well-ordered microstructures and controllable chemical compositions. Reliable manipulation of CO₂ gas bubble behavior can be achieved in CO₂ supersaturated aqueous solutions. The CO₂ bubbles generated on hydrophilic interfaces grew in situ and were then released with small diameters and spherical morphologies. The diameters of the CO₂ bubbles on hydrophilic interfaces decreased as a function of interfacial roughness. FAS modification enhanced the adhesion force between the hydrophobic interfaces and the CO₂ bubbles. The CO₂ bubbles grew with a spherical crown shape and then coalesced with their neighbors. They finally detached and formed large diameter interfaces. As the interface hydrophobicity and roughness increased, CO₂ pockets or continuous CO₂ films can be created among the rough microstructures.