Channel-controlled Janus membrane fabricated by simultaneous laser ablation and nanoparticles deposition for underwater bubbles manipulation

Abstract

Reliable manipulation of gaseous bubbles in aqueous media has spurred considerable research interest in recent years due to the tremendous potential ranging from water treatment, catalytic reactions to resource exploration and liquid medicine transportation. However, facile and effective manufacture of functional devices for bubble manipulation is still in great demand. Here, a versatile integrated femtosecond laser-assisted ablation and nanoparticles deposition (FLAND) approach is proposed to obtain Janus organic membranes having mesoscale pore arrays for unidirectional transportation of underwater bubbles. Selective silica nanoparticles deposition occurs simultaneously with laser ablation, enabling superaerophilic/superaerophobic Janus membranes without toxic chemical treatment and rigorous bonding. The FLAND method is capable of controlling the wettability of the pore channel, which is revealed to play a crucial role in the bubble penetration behavior. Analogous to an electrical diode, underwater unidirectional penetration of bubbles is demonstrated for gas-related implementations. This fabrication system with an identical femtosecond laser for simultaneous ablation and nanoparticles deposition manifests simplicity and versatility, opening up more possibilities in manufacturing functional surfaces for various applications.