A facile approach to transform stainless steel mesh into pH-responsive smart material

Abstract

The mixed modifiers of methyl-terminated thiol and carboxyl-terminated thiol were successfully assembled on stainless steel meshes (SSM) utilizing polydopamine as the adhesion layer and the strong thiol ligand with Ag. The microstructure, surface topography, chemical composition and wettabilities were investigated with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS) and contact angle meter, respectively. Importantly, the surface modified by mixed thiol show different responsive behavior to nonbasic and basic water droplets. Plus, the selectiveness of high water–oil repellence reveals the unique and smart tendencies of as-prepared functional stainless steel mesh. The reversible pH-response and stability have also been investigated. Based on stainless steel material widely used in engineering, this prepared smart material is expected to be used in many industrial applications, such as pH controllable dual oil–water on–off switch and diversified oil–water separation.