A magnetic-responsive conical microcolumn for removing oil pollution in pipelines and emulsion filtering with ultra-high separation flux

Abstract

Micro-oil droplets or little oil pollution in pipelines are difficult to remove in depth. Traditional superhydrophobic-superoleophilic materials cannot reach the designed area accurately. Herein, a novel magnetic-responsive conical microcolumn was prepared combined by additive manufacturing integration technology. The superhydrophobic-superoleophilic conical microcolumn could absorb micro-oil droplets and clean oil pollution in closed pipelines controlled by external magnetic field with high efficiency. The geometry character affects seriously oil driving behaviors. A larger aspect ratio and bottom diameter are conducive to fast oil movement with a velocity of up to 47.5 mm/s on the conical microcolumn when the aspect ratio is 1:2 and the bottom diameter is 3.5 mm. After optimizing geometric size, the conical microcolumn absorbs oil droplets with different sizes and surface energies, especially emulsified oil. Additionally, the conical microcolumns have ultra-high separation flux for various emulsions (oil-in-water: 19894 L/m2·h, water-in-oil: 42972 L/m2·h) and oil type detection property due to different oil movement velocity. Thus, the magnetic-responsive conical microcolumn is expected to be applied in droplet driving, oil pollution-cleaning, wastewater treatment, and oil type detection.