Abstract
The problem of oil-water separation regarding oil-containing brine has been of much concern when using the oil pad water dissolution method to construct salt cavern reservoirs. In this paper, oil-water separation materials with micro-nano hierarchical structure were prepared on different metal substrates using chemical etching and electrophoretic deposition. And hydrophobic materials with a single micro/nano structure were also prepared; then, the surfaces were hydrophobized by various low surface energy modifiers. Thereafter, we analyzed and compared the surface morphology, chemical composition, and wettability of all the materials and found that brine contact angles on hierarchical structure surfaces were above 160° while the diesel was completely diffused. Furthermore, preparation parameters affecting the surface morphology and wettability of micro-nano composite structures were explored. Meanwhile, it was found that the surface of prepared composite structure could still maintain super-hydrophobic/lipophilic properties after exposure in air for 6 months, sliding 60 cm on sandpaper, or immersion in diesel/brine for 48 h. Moreover, the composite structure surface displayed improved corrosion resistance with corrected self-corrosion potential and lower corrosion current density. It was equally observed that the studied materials could be better adapted to the actual context of salt cavern reservoir construction and thus have great application prospects.
Highlights
In recent years, China has been undertaking large-scale constructions of salt cavern reservoirs [1], which have been widely used to store crude oil, natural gas, and other substances around the world [2, 3]
We examined the morphology of micron and micro/nano sample surfaces by Field emission scanning electron microscope FTIR (FESEM)
It can be seen that the surface after chemical etching becomes rough and uneven, and a large number of microsized discontinuous pits and rectangular boss structures are formed on the surface
Summary
China has been undertaking large-scale constructions of salt cavern reservoirs [1], which have been widely used to store crude oil, natural gas, and other substances around the world [2, 3]. Erefore, it is of great engineering and research significance to conduct a study on oil-water separation materials that can be used in a brine environment in order to get an excellent different wettability to oil and water. It is preferable to introduce microand nanoscale hierarchical structures into the substrates for ensuring superhydrophobicity after surface damage Techniques such as chemical etching-anodic oxidation [29] and acid etching-boiling water immersion [30] are often used to create multiscale structures which are hydrophobized by low surface energy modifier. We modified the surface of the prepared nanostructure with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FAS) and stearic acid (STA), respectively, to study the effects of different low surface energy modifiers on the super-hydrophobic/lipophilic properties of the material. It was found that the sample surface maintains excellent super-hydrophobic/lipophilic properties after prolonged exposure to air and immersion in brine or diesel and exhibits superhydrophobicity for both acid and alkali droplets
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
