A self-cleaning underwater superoleophobic mesh for oil-water separation

Abstract

Oil–water separation has recently become a global challenging task because of the frequent occurrence of oil spill accidents due to the offshore oil production and transportation, and there is an increasing demand for the development of effective and inexpensive approaches for the cleaning-up of the oily pollution in water system. In this study, a self-cleaning underwater superoleophobic mesh that can be used for oil-water separation is prepared by the layer-by-layer (LbL) assembly of sodium silicate and TiO2 nanoparticles on the stainless steel mesh. The integration of the self-cleaning property into the all-inorganic separation mesh by using TiO2 enables the convenient removal of the contaminants by ultraviolet (UV) illumination, and allows for the facile recovery of the separation ability of the contaminated mesh, making it promising for practial oil-water separation applications.

A pH-responsive smart surface for the continuous separation of oil/water/oil ternary mixtures

“…Since the pioneering work of Jiang and co-workers 3 various superhydrophobic/superoleophilic materials have been developed for oil/water separation of oil-rich mixtures, including porous polymer membranes, 4 metal mesh, 3,[5][6][7] carbon nanotube network films 8 and polymer-nanoparticle composites. 9 Inspired by the oleophobicity of fish scales, several additional superhydrophilic/underwater superoleophobic materials have been proposed [10][11][12][13][14][15][16] in water-rich mixtures that allow water infiltration but prevent oil penetration when used underwater. These superhydrophilic/underwater superoleophobic materials [17][18][19] may very well solve the problems of oil blocking that occurred in the system of water/oil with lower density than water during the separating process in conventional superhydrophobic/superoleophilic oil/water-separating materials.…”

Separation of organic liquid mixture by flexible nanofibrous membranes with precisely tunable wettability

“…The mechanisms of membrane separation are based on exact opposite wettabilities toward oil and water, including superhydrophobic/superoleophilic membranes 3,5-8 or superhydrophilic/superoleophobic membranes. [9][10][11][12][13][14][15] For example, superhydrophobic/oleophilic membranes have been prepared from various materials, including metals, polymers or even clothes and filter papers, that could intercept water and allow oil to pass through. [16][17][18][19][20] In addition, researchers have gained inspiration from oil-contaminantfree fish skin to fabricate oil-repellent hydrogel membranes that could separate oil from water.…”

Study of Factors Governing Oil–Water Separation Process Using TiO2 Films Prepared by Spray Deposition of Nanoparticle Dispersions

“…22,23,25 Various preparation methods such as layer-by-layer coating, polymerization, sol gel method, hydrothermal treatments, direct oxidation, and chemical vapor deposition, have been employed, and various materials such as hydrogel, silicate, TiO 2 , silica gel, zeolite and nanostructured ZnO surfaces, have been studied in order to achieve superhydrophilic surface with good underwater oil repellency. 22−27 However, most of these preparation methods involve multiple processes, long and delicate methods of sample preparation, exotic materials, and extreme physical conditions to achieve a surface with such wetting properties.…”