Corrosion-Resistant Hydrophobic MFI-Type Zeolite-Coated Mesh for Continuous Oil–Water Separation

Abstract

Efficient separation of oil–water mixtures has become a critical challenge due to frequent oil-spill accidents and enormous release of oil-containing wastewater by households or catering services. Superhydrophobic coatings on metal meshes have been evidenced as the effective and energy-saving materials for oil–water separation. However, it is difficult to fabricate the separating coatings with long-term superhydrophobicity and the outstanding anticorrosion properties for practical application. In this study, we fabricated the hydrophobic Mobil five (MFI)-type zeolite coatings on the pristine stainless steel meshes via an in situ crystallization method and subsequently modified them with an environmentally safe hexadecyltrimethoxysilane compound. The as-prepared coating meshes showed good self-cleaning, antifouling, and anticorrosion properties. Furthermore, the coated meshes were capable of continuously and efficiently separating different kinds of oil–water mixtures under gravity-driven pressure and had more than 99.0% high separation efficiency. More important, the prepared hydrophobic MFI-coated meshes had equivalent separation performance compared to that of superhydrophobic coating meshes. Meanwhile, the hydrophobic MFI-coated meshes demonstrated excellent reusability performance and long-term stability. These as-prepared meshes thus have great potential for applications in separating oily wastewater from oil fields as well as recycling of waste oil from catering services.