Alkylsilyl protected amino acid based versatile organogelator for potential oil spillage recovery and waste water treatment

The present work reports the synthesis of L-3,4-dihydroxyphenylalanine (L-DOPA) based small molecule organogelator 1 where the two phenolic –OH groups are protected by tertiary-butyldimethylsilyl (TBDMS) moiety. The amphiphile 1 exhibits excellent gelation properties in wide range of solvents ranging from aromatic solvents, alcohols, chlorinated solvents, petroleum fractions and crude oil. The minimum gelation concentration (MGC) varies from 0.25 to 1.5% (w/v) in these solvents. Formations of these gels are instantaneous and are thermoreversible in nature. Various spectroscopic and microscopic studies such as field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) etc. confirmed the crucial role of non-covalent interactions in gel formation. Rheological experiments confirmed the mechanical stability and viscoelastic nature of the prepared gels. Interestingly, gelator 1 exhibits selective gelation of various petroleum fractions like petrol, diesel, and kerosene from a biphasic mixture of oil-water. Gelator 1 also exhibits selective gelation of crude oil having high and low sulphur content from a biphasic mixture of oil-sea water. Additionally, the xerogels from 1 are useful in removing various toxic dyes from wastewater. Additionally, the xerogels from 1 are useful in removing various toxic dyes from wastewater having adsorption capacity of 6.8–19.0 mg of dye per 1 g of xerogel in 24 h.