A Superhydrophobic Copper Mesh with Microrod Structure for Oil–Water Separation Inspired from Ramee Leaf

Abstract

It is well known that superhydrophobic surfaces with unitary microstructures (such as the lotus leaf) have better surface mechanical properties than those with binary micro-and nanostructures (such as the ramee leaf). Rodlike unitary structured films are fabricated on copper meshes via a facile and simple chemical vapor corrosion method. Following the surface modification of 1-decanethiol (C 10 H 22 S), the resultant films exhibiting superhydrophobicity and superoleophilicity can be applied to separate the oilwater mixture.In recent years, with the development of extreme wettability, more potential applications based on it are explored, including anti-icing, antifogging, water-collecting, and antifouling applications.1 Oilwater separation has led to wide concerns since Jiang et al.2 first reported an example to separate oil from water by using superhydrophobic and superoleophilic Tefloncoated meshes. Henceforth, many porous substrates such as metallic mesh films, 3 foams, 4 textiles, 5 filter papers, 6 and sponges 7 have become popular to achieve oilwater separation by combining rough morphology with low-surface-energy compounds. Various methods have been employed to fabricate diverse rough morphologies. 812 For example, Jiang et al. 11constructed aligned ZnO nanorod array on a stainless steel mesh with photoinduced oilwater separation via a two-step solution-growth approach. Based on a solgel method, Miyake et al. 12 prepared a TiO 2 film composed of uniform fine grains on the Ti mesh, exhibiting underwater superoleophobicity after UV irradiation, to be applicable as an oilwater separation filter. Our group 13,14 have also made efforts to separate oil and water. Inspired from the butterfly wing, we fabricated superhydrophobic copper mesh films by electroplating Cu nanoparticles on the as-cleaned copper mesh films, followed by thiol grafting. The fabricated films showed efficient and rapid oilwater separation ability and could be used for numerous times. Moreover, we further achieved pH-responsive bidirectional oilwater separation by modifying a thiol mixture of HS(CH 2 ) 9 CH 3 and HS(CH 2 ) 10 COOH on hierarchical copper wires coated with Cu nanoparticles.14 Importantly, in our previous research, 15 we found that the surface mechanical properties of superhydrophobic surfaces with unitary microstructures are better than the surfaces with binary micro-and nanostructures. It is still a challenge for us to fabricate biomimetic superhydrophobic surfaces with good mechanical properties because it is very important for them to be applied in industry.Recently, many superhydrophobic surfaces have been applied to separate oilwater mixtures and the metal meshes such as copper mesh were widely used to fabricate the superhydrophobic surfaces for such separations. However, most of the methods are time-consuming and complicated. Herein, a facile chemical vapor corrosion method is employed to fabricate a unitary microstructured Cu(OH) 2 film. Combined with the surface modification of 1-decanethiol (C 10 H 22 S) to reduce the...

FAS Grafted Electrospun Poly(vinyl alcohol) Nanofiber Membranes with Robust Superhydrophobicity for Membrane Distillation

“…Although great progress has been made in the preparation of superhydrophobic ENMs via generating a hierarchical structure, the laundering durability of such superhydrophobic membranes in cross-flow operations remains a concern due to the weak adhesion between the nanofibers and nanopartilces. It has been reported that superhydrophobic surfaces with unitary microstructures such as the ramee leaves possess better mechanical properties than those with binary micro- and nanostructures. − Herein, we describe a new strategy to fabricate ENMs with robust superhydrophobicity by mimicking the unitary microstructures of ramee leaves via eletrospinning of poly­(vinyl alcohol) (PVA), followed by chemical cross-linking and surface fluorination. PVA has been selected as the membrane material with respect to its inexpensive cost, excellent chemical stability, and functional hydroxyl groups .…”

Bionic superhydrophobic surfaces based on topography of copper oxides

“…The butterfly wings are composed of oriented micron scales and nano-strips F I G U R E 3 Natural Superhydrophobic surfaces (SHSs) with isotropic structures. (a) Ramie leaves [6]. (b) Chinese watermelon [7].…”

Facile Fabrication of Superhydrophobic Copper- Foam and Electrospinning Polystyrene Fiber for Combinational Oil–Water Separation

“…The pine-cone-like hierarchical micro-nanostructure [23], the surface distributed grooves and ridges in micrometer scale and many nano-wrinkles [24], and the unique nanoworm-like structure [25] were mainly modified by fluorosilane previously. Also, some other examples involve rodlike nanostructures of Cu(OH) 2 [26,27], highly dense ordered Cu 2 O nanorods [28], flower-like [29], leaves-like, and wormlike micro-/nano-scale structures [30,31], and these hydrophobic surfaces were finally modified by n -alkanethiolates [32]. To some extent, the techniques described above were efficient for separating mixtures of water and oil, however, there are some disadvantages that need to be overcome, such as time-consuming and complicated fabrication, special equipment, and expensive materials.…”