Zeolite-coated mesh film for efficient oil–water separation

TLDR

Oil–water separation is urgently needed to mitigate industrial oily wastewater and oil spills, yet creating energy‑efficient, stable membranes remains challenging, prompting interest in zeolite films for their unique pore structure and robust stability. This work demonstrates zeolite‑coated mesh films that enable gravity‑driven oil–water separation. The films are fabricated by controlling zeolite crystal growth time to tune pore size, which adjusts flux and intrusion pressure for efficient separation. They achieve high separation efficiency through superhydrophilicity and underwater superoleophobicity, and remain corrosion‑resistant in harsh media, indicating practical applicability.

Abstract

Oil–water separations are helping with urgent issues due to increasing industrial oily wastewater, as well as frequent oil spill accidents. Membrane-based materials with special wettability are desired to separate oils from water. However, fabrication of energy-efficient and stable membranes that are suitable for practical oil–water separation remains challenging. Zeolite films have attracted intense research interest due to their unique pore character, excellent chemical, thermal and mechanical stability, etc. Here we first demonstrate zeolite-coated mesh films for gravity-driven oil–water separation. High separation efficiency of various oils can be achieved based on the excellent superhydrophilicity and underwater superoleophobicity of the zeolite surface. Flux and intrusion pressure are tunable by simply changing the pore size, dependent on the crystallization time of the zeolite crystals, of the zeolite meshes. More importantly, such films are corrosion-resistant in the presence of corrosive media, which gives them promise as candidates in practical applications of oil–water separation.