Hydrogels for oil-water separation application

Facing the severe challenge of the continuous global growth in the volume of oily wastewater, the efficient oil-water separation is crucial for protecting the environment and safeguarding human health and safety. Due to low cost, wide availability and environmental compatibility, hydrogels have been widely applied in the field of oil-water separation. Herein, this review comprehensively analyzes hydrogel types for oil-water separation, focusing on their core separation mechanisms. Meanwhile, we point out the current limitations of hydrogels in oil-water separation, such as insufficient mechanical properties, relatively high cost and complex preparation processes. Furthermore, this review explores the preparation and modification strategies of hydrogels, which include wettability regulation, mechanical property enhancement, additional stimuli-responsiveness introduction, anti-fouling/antibacterial modification and self-healing functions construction. To address developmental demands for hydrogel industrial application, this review focuses on the application research of continuous oil-water separation equipment to clarify current research progress and key challenges. Finally, we summarize challenges currently faced by hydrogels in oil-water separation, and identify future research directions aligned with cutting-edge development trends such as numerical simulation, machine learning, intelligent regulation and industrial applications, so as to promote the research development and industrial application of hydrogels in oil-water separation.