Fabrication of a Janus Copper Mesh by SiO₂ Spraying for Unidirectional Water Transportation and Oil/Water Separation

Abstract

Massive discharge of oily wastewater and frequent occurrence of offshore oil spills have posed an enormous threat to the socioeconomic and ecological environments. Janus membranes with asymmetric wettability properties have great potential for oil/water separation applications and have attracted widespread attention. However, existing Janus membranes still suffer from complex and costly manufacturing processes, low permeability, and poor recyclability. Herein, a novel and facile strategy was proposed to fabricate a Janus copper mesh with opposite wettability for unidirectional water transport and efficient oil/water separation. The hydrophilic side of the Janus copper mesh was prepared by coating it with Cu(OH) 2 nanoneedles via a chemical oxidation method. The hydrophobic side was fabricated by coating it with hydrophobic SiO 2 nanoparticles via a facile spraying method. The as-prepared Janus copper mesh showed asymmetric surface wettability, which can achieve unidirectional water transport and efficient oil/water separation with excellent recyclability, exhibiting great application potential for droplet manipulation and wastewater purification.

Impact of SiO2 doping on the structure and oil–water separation properties of a PVDF membrane: insights from molecular dynamics simulation

“…Similarly, Bai's lab 40 investigated the effects of the size of silica particles on the diffusion behavior of water in SiO 2 /PVDF hybrid membranes. Even though more simulation work 41–43 has been done, the interaction mechanism between particles and membrane, as well as the surface interaction between oil/water and hybrid membrane, is still not clear. Furthermore, how the nanoparticles affect the separation of oil–water emulations remains uncertain.…”