Simple and Low-Cost Oil/Water Separation Based on the Underwater Superoleophobicity of the Existing Materials in Our Life or Nature

Abstract

The achievement of high-efficiency oil/water separation has huge implications for protecting environment and reducing economic losses, but there is still a great challenge. Currently, most artificial oil/water separating materials are fabricated through complex preparation process, resulting in the very high cost of separation. In this paper, we present a simple and low-cost method to achieve oil/water separation by using the underwater superoleophobic materials that already exist in our life or nature. Taking filter paper and zeolite layer as examples, we show the inherent porous microstructures of these materials. Such porous microstructures endow filter paper and zeolite layer with strong ability to absorb water and the underwater superoleophobicity. Based on the porous feature and underwater superoleophobicity, the pre-wetted filter paper and zeolite layer can be used to effectively separate the mixture of water and oil, with great separation capacity. The existing materials (e.g., filter paper and zeolite layer) with both porous microstructure and underwater superoleophobicity in our life or nature are green and low-cost, and can be easily obtained. Such advantages allow those materials to potentially solve the pollution problems caused by the discharge of industrial oily wastewater and the oil-spill accidents.

Mini-Review on Bioinspired Superwetting Microlens Array and Compound Eye

“…Reproduced from Li M. et al ( 2019a ) with the permission of the WILEY-VCH. Reproduced from Bian et al ( 2020 ) with the permission of Bian et al Reproduced from Raut et al ( 2015 ) and Li J. et al ( 2019 ) with the permission of the American Chemical Society. Reproduced from Li M. et al ( 2019b ) with the permission of Li et al…”

“…Similar to the superhydrophobic MLA pattern, Bian et al ( 2020 ) prepared an underwater superoleophobic MLA pattern on a transparent K9 glass substrate through the ingenious combination of the smooth microlenses and the laser-induced rough micro/nanostructures, as shown in Figures 2G,H . The smooth MLA can be used for underwater imaging while the surrounding microstructures endow the sample with underwater anti-oil ability.…”

Emerging Separation Applications of Surface Superwettability

“…It is widely demonstrated that the mixture of oils and water can be effectively separated by porous materials with either superhydrophobicity or underwater superoleophobicity [63][64][65][66][67][68][69][70]. Such a separation is supported by the phenomenon that oils and water have different wetting behaviors on those superwetting separation materials [71][72][73][74][75][76][77][78][79][80]. The oil/water mixture is just the tip of the iceberg, and many other mixtures also need to be separated.…”

Effect of Membrane Materials and Operational Parameters on Performance and Energy Consumption of Oil/Water Emulsion Filtration

“…Efficient management of industrial oil/water emulsion wastewater has been a challenge due to poor efficiency of conventional treatment methods [ 1 , 2 , 3 ], especially when treating emulsion with fine oil droplet sizes of <2 µm [ 4 ]. Dissolved air floatation and many other conventional methods are capital intensive and involve generation of secondary waste [ 5 , 6 ].…”