A new aromatic amino acid based organogel for oil spill recovery

Abstract

An aromatic amino acid (phenylglycine) based amphiphile with amide and ester groups and a long fatty acyl chain has been found to form organogels selectively in the fuel hydrocarbon solvents including hexane, heptane, cyclohexane, diesel, kerosene and pump-oil at room temperature. Organogels have been well characterized morphologically by field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). Morphological studies of these xerogels have revealed the presence of fascinating right-handed twisted nanoribbons (in n-heptane and n-octane). Involvement of different non-covalent interactions among the gelator molecules within the gel matrix has been studied using FT-IR and XRD. The organogel in diesel is mechanically stable with high yield stress (177.8 Pa) and storage modulus (>10⁴ Pa) values, as has been evidenced from the rheological studies. Interestingly, this gelator compound exhibits phase selective gelation properties and the phase selective gelation occurs efficiently and quickly (within 90 s), in oil–water mixtures and the gelator molecule can be recovered and reused several times easily, indicating its applicability in oil spill cleaning.