Laser-structured Janus wire mesh for efficient oil–water separation

Abstract

We report here the fabrication of a Janus wire mesh by a combined process of laser structuring and fluorosilane/graphene oxide (GO) modification of the two sides of the mesh, respectively, toward its applications in efficient oil/water separation. Femtosecond laser processing has been employed to make different laser-induced periodic surface structures (LIPSS) on each side of the mesh. Surface modification with fluorosilane on one side and GO on the other side endows the two sides of the Janus mesh with distinct wettability. Thus, one side is superhydrophobic and superoleophilic in air, and the other side is superhydrophilic in air and superoleophobic under water. As a proof of concept, we demonstrated the separation of light/heavy oil and water mixtures using this Janus mesh. To realize an efficient separation, the intrusion pressure that is dominated by the wire mesh framework and the wettability should be taken into account. Our strategy may open up a new way to design and fabricate Janus structures with distinct wettability; and the resultant Janus mesh may find broad applications in the separation of oil contaminants from water.

Janus Membranes: Creating Asymmetry for Energy Efficiency

“…Similar structures can be obtained by single‐sided photocrosslinking (Figure f) . This concept also applies to single‐sided etching or femtosecond laser processing for Janus membrane fabrication. In these methods, the thickness of each layer was adjusted by radiation or etching time.…”

A Review of Femtosecond‐Laser‐Induced Underwater Superoleophobic Surfaces

“…Recently, Sun et al reported the fabrication of a Janus wire mesh toward its applications in efficient oil/water separation . Laser‐induced periodic surface structure was first formed on both sides of a copper mesh by femtosecond laser processing.…”

Femtosecond Laser Micro/Nano-manufacturing: Theories, Measurements, Methods, and Applications

“…With respect to oil-water separation, conventional oil-water separation methods are limited by poor reliability, complicated preparation processes, and low reusability. The use of femtosecond laser fabrication can help to effectively overcome these limitations [101][102][103], and it was employed to fabricate an ultrathin aluminum foil to form a novel film consisting of nanostructured microporous arrays by a femtosecond laser, which can realize underwater superoleophobicity (OCA > 150°) and an oil-water separation function. In addition, microholes with a strong filtering effect for particles of different sizes were fabricated on a titanium foil by femtosecond laser microhole drilling, as shown in Figs.…”