Underwater Smart Wetting Protic Ionic Liquid‐Infused Starch‐Based Hydrogel for Efficient Oil Removal

Abstract The discharge of oily wastewater from industries and domestic usage leads to drastic environmental issues, including the destruction of precious natural resources and creating a threat to the survival of aquatic species. Hence, segregation of oil/water mixtures and stable emulsion has emerged as a global issue. Hydrogels based on starch/PVA (polyvinyl alcohol) were synthesized by incorporating the minute amount of protic ionic liquid, enhancing the gels' cavities crosslinked with glutaraldehyde. FT‐IR and PXRD techniques were executed to characterize the gel. FE‐SEM carried off surface topographical analysis. Wettability was evaluated using oil and water in ambient and submerged conditions, which indicates the super‐hydrophilic and super‐oleophobic features of these gels. The gel shows no contact angle in the air for both oil and water. Ultimately, when submerged, it depicts the super‐oleophobic behavior, with an oil contact angle of more than 150°. The gel was highly efficient for eliminating oil from water. It has the efficiency of water recuperation better than 99%. The hydrogel tends to be employed time after time for the segregation process. Still, efficiency was higher than 99%, after exceeding 10 cycles. Furthermore, the separating gels exhibited high water flux, highlighting their potential for efficient large‐scale separation processes.