Reversibly switching water droplets wettability on hierarchical structured Cu2S mesh for efficient oil/water separation

Abstract

Surfaces with reversible wettability have broad applications but remain challenging since the switching process is usually energy intensive and complex. In this paper, a pyramid shaped Cu 2 S film with hierarchical micro/nanostructures is formed on a commercial copper mesh. This film is formed by a spontaneous redox sulfuration reaction and results in a roughened surface, which enables reversible wetting transition between superhydrophilicity to superhydrophobicity. This switching occurs by simple processes such as alternately storing in air or using an ethanol solution treatment and yields cyclic wettability switching for many cycles. This convenient wetting transition behavior, as well as strong stability and efficient oil/water separation with efficiency exceeding 98%, renders it as a potentially useful mesh material for switchable surfaces.

A Rapid Effervescent Route to Rational Activation of Cu/g‐C3N4 and bulk MoS2 Cocatalyst for Highly Efficient and Robust Photo‐Fenton Process

“…The Cu 2p XPS spectra (Figure 1g) is related to Cu + (933.2 and 952.9 eV), Cu 2+ (935.4 and 955.4 eV), and satellites (943.6 and 963.6 eV). [30] Unlike similar systems, the results affirm the coexistence of Cu + and Cu 2+ in our system. [31] The oxidizing atmosphere during the effervescence process caused by sodium dichloroisocyanurate generates the proper oxidation state in Cu-CN-ef, contributing to improved hydrophilicity and an ideal interface for synergistic MoS 2 .…”

Reversible Wettability between Underwater Superoleophobicity and Superhydrophobicity of Stainless Steel Mesh for Efficient Oil–Water Separation

“…The sample was immersed in ethanol with a low surface energy, and then the microstructure of the sample was filled with ethanol. After the mesh was removed from the ethanol and placed in water, the ethanol in the microstructure was dissolved in water to form a water film, thus the oil formed a stable Cassie model on the surface …”

“…After the mesh was removed from the ethanol and placed in water, the ethanol in the microstructure was dissolved in water to form a water film, thus the oil formed a stable Cassie model on the surface. 38 The bouncing behaviors of underwater oil (1,2-dichloroethane) droplets on the SSM with ethanol immersion and natural drying treatments are shown in Figure 3a,b and Video S1 (Supporting Information). Before the oil droplet hits the surface of SSM, the falling process is affected by the combined effect of gravity and water resistance, so the shape of the oil droplet is ellipsoid.…”

Facile and scalable preparation of superhydrophobic brass mesh for efficient and rapid separation of oil and water

“…The setup shown in Fig. 14 and similar ones, in which water remained on the superhydrophobic mesh, were commonly used in various research [43][44][45][46] . Due to covering the mesh surface with water, such setups cannot be generalized in industrial applications, especially for heavy oils' separation.…”