Bioinspired Anti-Oil-Fouling Hierarchical Structured Membranes Decorated with Urchin-Like α-FeOOH Particles for Efficient Oil/Water Mixture and Crude Oil-in-Water Emulsion Separation

Abstract

Designing and constructing a stable water-retention layer acting as the isolation between the oil and membrane surface holds great significance for solving the membrane fouling problems in oil/water separation, including common layered oil/water mixtures, immiscible oil-in-water emulsions, and even high-viscosity crude oil-in-water emulsions. Inspired by the self-cleaning property of sea urchin thorns, a bioinspired anti-oil-fouling hierarchically structured membranes decorated with urchin-like α-FeOOH particles was successfully prepared via the layer-by-layer (LBL) self-assembly method, maintaining numerous effective micro-nanopores. The hierarchical structured membrane exhibited superior superhydrophilicity/underwater superoleophobicity, high water-retention ability, and preferable anti-oil-fouling properties. Furthermore, the biomimetic membrane with controllable pore sizes could not only separate common layered oil/water mixtures but also effectively separate immiscible surfactant-stabilized oil-in-water emulsions of both low-viscosity crude oil and high-viscosity crude oil with an ultrahigh water flux up to 2598.4 L m–2 h–1 and an outstanding separation efficiency of 98.5%, revealing its promising prospect in oily wastewater treatment.

Overflow Control for Sustainable Development by Superwetting Surface with Biomimetic Structure

“…On 22 March 2021, World Water Day raised awareness of the global water crisis and appealed to valuing water to support the achievement of Sustainable Development Goal 6: availability and sustainable management of water and sanitation for all by 2030 . To address this issue and achieve the goal of carbon peak by 2030 and carbon neutralization by 2060, researchers focused on finding sustainable sources of freshwater by harvesting water from atmospheric fog, ,,,− producing water from saline water desalination, ,,,,− and wastewater treatment. ,,,− …”

Superwetting surfaces for filtration separation of high-viscosity raw petroleum/water mixtures

“…Due to the rigid rough structure and a large number of hydrophilic molecules on the surface, inorganic materials have attracted attention as another class of robust antifouling materials, such as TiO 2 and SiO 2 , 19 two-dimensional materials containing transition metal carbides and nitrides (MXene), 116 FeOOH, 112 etc. Yang et al 19 prepared crude oil rejection membranes via atomic layer deposition of TiO 2 or SiO 2 on the surface of PVDF membranes.…”

“…Zhang et al 106 deposited Ti 3 C 3 T x on a porous PVDF membrane via a facile vacuum filtration process to synthesize an MXene membrane, which showed an excellent separation efficiency of more than 99.4% for emulsified crude oil-in-water mixtures while exhibiting exceptional durability in corrosive liquids of acids and salts. Yin et al 112 constructed micro-nano hierarchical structures similar to the shape of sea urchins on the membrane surface to reduce the contact area between oil droplets and the membrane surface, thereby improving the anti-oil fouling performance. They decorated the membrane surface with oil sea urchin-like α-FeOOH particles by a layer-by-layer self-assembly method.…”

Advances of Adsorption and Filtration Techniques in Separating Highly Viscous Crude Oil/Water Mixtures

“…Inorganic materials, such as TiO 2 , [ 137 ] CaCO 3 , [ 138 ] FeOOH, [ 134 ] and 2D materials with transition metal carbides and nitrides (MXene), [ 139 ] are another category of robust antifouling material benefiting from their rigid rough structure and many hydrophilic groups. Darling et al.…”