Multi-layer superhydrophobic nickel foam (NF) composite for highly efficient water-in-oil emulsion separation

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2021-11, Vol.628, p.127299, Article 127299
• Main Authors: Wang, Yi, Zhao, Siyang, Guo, Zhiguang, Huang, Jinxia, Liu, Weimin
• Format: Article
• Language: English
• Subjects: Multi-layer; Nickel foam; Suspension immersion; Underoil superhydrophobic; Water-in-oil emulsion separation
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2021.127299

Taking sponge-like porous nickel foam (NF) with a pore size of about 100 µm as the carrier, superhydrophobic carbon nanoparticles (CNPs) as the filler, and hydrophobic polydimethylsiloxane (PDMS) as the binder, a single-layer superhydrophobic nickel foam composite (NF/CNP-PDMS) is prepared by the simple immersion method. Then the single-layer is laminated into a multi-layer composite with high porosity and micro-nano rough structure for water-in-oil emulsion separation. In addition, in the pressing process, the factors affecting the flux and efficiency of emulsion separation are explored by controlling the areal density and thickness of the three-dimensional multilayer material. As a consequence, the surface of the micro-nano structure has a static water contact angle (WCA) of about 150°. When the areal density is 875 g/m2, the thickness is 2 mm, and the efficiency of emulsion separation is as high as 98%. Moreover, the NF/CNP-PDMS has excellent chemical stability, mechanical durability and abrasion resistance, which can be reused for emulsion separation. This work is one of the few experimental schemes using foamed metal for emulsion separation. And the number of pressed layers of nickel foam can be changed to meet different needs of emulsion separation. This work will be beneficial to the research of stable underoil superhydrophobic materials and efficient emulsion separation device. Using sponge-like porous nickel foam as the carrier, superhydrophobic carbon nano-particles as the filler and hydrophobic polydimethylsiloxane as the binder, a three-dimensional multilayer emulsion separation membrane with mechanical and chemical stability were prepared by simple immersion, heating curing and pressing methods (separation efficiency exceeds 95%). [Display omitted] •The experiment is simple, low-cost and follows the principles of green chemistry.•The 3D membrane can separate the emulsion under the action of gravity, and the separation efficiency exceeds 95%.•The filling of carbon nanoparticles-polydimethylsiloxane greatly improves the corrosion resistance of the nickel foam.