Phase selective organogel from an imine based gelator for use in oil spill recovery

Marine oil spills create a serious problem for the environment by destroying ecosystems, and the adulteration of fuel oils is also a serious problem, as the optimum performance of an engine is affected by damaging its parts. To save the environment and prevent adulteration, a number of Schiff base-derived organogelators (OG-1, OG-2 and OG-3) are synthesized with different pendant groups containing anthracene, pyrene and cyclohexane moiety, respectively. They exhibit thermo-reversible gelation behavior in organic and mixed solvents. Only OG-1 produces gels in most organic solvents and also in fuel and edible oils, indicating it to be a smart gelator. It exhibits thixotropic behavior with very high yield stress, while the other gels do not exhibit thixotropic properties. Spectroscopic and X-ray studies indicate the concomitant presence of H-bonding, -stacking and van der Waals interactions in the OG-1 gel; however, the OG-2 and OG-3 gels do not exhibit all these interactions, making weaker gels. Due to its superior gelling property, the OG-1 gel is tacitly used to detect fuel oil contamination mainly in diesel and petrol using fluorescence behavior, and the phase selective gelation of OG-1 promotes it as a successful recyclable material for oil spill recovery from oil-water mixtures, even in the presence of salts, acids and bases.