High-Flux and Robust Co₃O₄ Mesh for Efficient Oil/Water Separation in Harsh Environment

Abstract

Material with special wettability for oil/water separation has drawn more and more attention, since the oil spill accidents and industrial processing are growing in frequency and in volume. A superhydrophilic and underwater superoleophobic mesh was prepared by introducing Co 3 O 4 on a stainless steel mesh, through a simple hydrothermal process and subsequent calcination. The as-prepared Co 3 O 4 mesh can not only separate various oil/water mixtures with high efficiency and high flux, but also work effectively in harsh environment such as highly acidic, alkaline, and salty solutions. Moreover, the Co 3 O 4 mesh can still retain good separation performance after 40 abrasion cycles with sandpaper. The outstanding anticorrosion and antiabrasion behaviors make the Co 3 O 4 mesh promising for oil/water separation even in harsh environment.

Biomimetic Mineralization to Fabricate Superhydrophilic and Underwater Superoleophobic Filter Mesh for Oil–Water Separations

“…The highest value appears in a kerosene mixture with a flux close to 500 kL·m –2 ·h –1 . According to the other as-prepared materials for oil–water separation in recent literatures, the reported flux value is in the range of 5–200 kL·m –2 ·h –1 , − which is much lower than that of the present work. , The results showed the mineralized filter mesh with an extremely high permeation rate, which is well consistent with the high-speed permeability demonstrated by completing the superhydrophilic dynamic infiltration process within just 24.9 ms in Figure b. This high-flux feature, which requires only gravity drive, can save energy in the separation process and is more likely to achieve economic benefits in practical large-scale oil–water separation applications.…”

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

“…As shown in Figure 3c,d, the CA values of underwater oil and water droplets are studied to evaluate the chemical durability of SSM in a harsh environment. After immersing in the corrosive solution with different pH values (1,5,8,12) and various metal ions (1 M NaCl, 1 M FeCl 3 ) for 24 h, the contact angles of underwater oil and water droplets have only changed slightly, but both have remained above 150°. The prepared surface still has the ability of wettability conversion via ethanol immersion and natural drying treatment.…”

“…Over the past few decades, water pollution caused by offshore oil exploration, oil tanker leakage, and industrial wastewater discharge has attracted widespread attention worldwide, which has led to not only serious environmental pollution but also huge economic loss. − Therefore, a cost-effective method to treat oil wastewater is highly desired. Inspired by the lotus leaf, springtail, and striped scale in nature, special wettability surfaces have recently received extensive attention of researchers because of their significance in diverse fields including self-cleaning, − antifogging, − anti-icing, − corrosion resistance, − and drag reduction. − With in-depth research on wettability, some of these materials are widely used in the treatment of oily wastewater. − In general, advanced materials based on special wettability can be classified into two types in the oil–water separation field: the “oil-removing” surface with superhydrophobic/superoleophilic properties can complete the separation of heavy oil–water mixture (heavy oil means that the density of oil is greater than that of water), and the “water-removing” surface with superhydrophilic/underwater superoleophobic properties can finish the separation of light oil–water mixture. − Particularly, the smart interface with switchable wettability is particularly interesting, , which can separate both light and heavy oil–water mixtures using the different circumstance stimuli. , For example, Zhang et al prepared the nylon membrane via the hydrothermal route, which attained switchable wetting properties upon changing the temperature .…”

Preparation of porous PTFE/C composite foam and its application in gravity‐driven oil–water separation

“…However, the exploitation of porous superhydrophobic filtration media with durable performance that can be used in harsh environment remains a great challenge 26–30 . The selection of material and the construction of structure are key to achieving the durability of filtration media.…”

“…However, the exploitation of porous superhydrophobic filtration media with durable performance that can be used in harsh environment remains a great challenge. [26][27][28][29][30] The selection of material and the construction of structure are key to achieving the durability of filtration media. It is well known that polytetrafluoroethylene (PTFE) has the advantage of chemical and temperature resistance, which means that it is one of the optimal choices for filtration media with durable performance.…”