The Influence of Surface Modification of Porous Materials to Improve the Efficiency of Separation of Water-Oil Emulsions: A Review

Water/oil (W/O) emulsions are formed during oil fields and production development, thereby reducing the oil quality. In order to separate the emulsions, specialists use various methods, equipment, and materials. Most emulsions formed during oil production are stable and persistent, and traditional methods such as sedimentation and centrifugation are ineffective in the separation process. Addressing this challenge, porous materials characterized by selective super-wetting properties are used for the high-quality separation of stable W/O emulsions. Therefore, this review presents recent advancements in highly porous cellular materials that separate W/O emulsions. It further discusses the features, limitations, and advantages of using superhydrophobic/superleophilic and superhydrophilic/superleophobic porous materials such as metallic and polymeric foams. The influence of the structure and nature of porous materials on the efficiency of the separation of W/O emulsions is analyzed. Additionally, this review also explores methods for modifying highly porous materials to improve selective wettability.