Peptide-based ambidextrous bifunctional gelator: applications in oil spill recovery and removal of toxic organic dyes for waste water management

Abstract

A low molecular weight peptide-based ambidextrous gelator molecule has been discovered for efficient control of water pollution. The gelator molecules can gel various organic solvents with diverse polarity, e.g. n-hexane, n-octane, petroleum ether, petrol, diesel, aromatic solvents like chlorobenzene, toluene, benzene, o-xylene and even aqueous phosphate buffer of pH 7.5. These gels have been thoroughly characterized using various techniques including field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction analysis, small angle X-ray scattering and rheological experiments. Interestingly, hydrogel obtained from the gelator molecule has been found to absorb toxic organic dyes (both cationic and anionic dyes) from dye-contaminated water. The gelator molecule can be reused for several cycles, indicating its possible future use in waste water management. Moreover, this gelator can selectively gel petrol, diesel, pump oil from an oil–water mixture in the presence of a carrier solvent, ethyl acetate, suggesting its efficient application for oil spill recovery. These results indicate that the peptide-based ambidextrous gelator produces soft materials (gels) with dual function: (i) removal of toxic organic dyes in waste water treatment and (ii) oil spill recovery.