Underoil Superhydrophilic Flame-Retardant 3d Porous Composite for Efficient On-Demand Emulsion Separation: Interface Engineering Design on Sphagnum Moss

Abstract

The large amount of oil sewage in the world has great harm to the environment, and the water in the lubricating oil will cause harm to the tribological properties. The underoil superhydrophilic surface is of great significance for realizing the on-demand separation of oil-water emulsion, and realizes the removal of water in the oil and oil in the water. A 3D porous emulsion separation material based on the hydrophilic principle of sphagnum moss was designed. The hydrophilicity and micro-nano rough structure was introduced by the self-polymerization of dopamine and mussel adhesion effect, as well as the superhydrophilic BaSO4 nanoparticles. The synergy of the two gives OSPC excellent selective wetting capability (water contact Angle of 0°, oil contact Angle of 157.3°), resulting in excellent separation performance for both oil-in-water and oil-in-water emulsions. OSPC has excellent adsorption capacity, which can absorb 74.38 times of its own weight of water, and still maintain a high adsorption capacity after cyclic adsorption. More importantly, OSPC filtration and separation efficiency of oil-in-water emulsion can reach 99.92%. It can still reach 99.84% after ten cycles of separation. At the same time, OSPC can quickly adsorb water to separate water-in-oil emulsion, with separation efficiency up to 99.82%. The efficiency almost changes after ten cycles of separation. In addition, the hydrophilic material has excellent flame-retardancy, reducing the possibility of secondary disasters. The synthesized 3D porous sponge has excellent on-demand separation performance, which broadens the preparation path of underoil superhydrophilic materials and provides application ideas for special wettability oil-water separation materials in oil wastewater treatment and lubricating oil dehumidification.

Keywords: Porous, Wettability, separation, emulsion