Sugar-benzohydrazide based phase selective gelators for marine oil spill recovery and removal of dye from polluted water

摘要

The synthesis of 3,4,5-tri-O-benzohydrazide based N-glycosylamines were characterized using NMR (H-1 and C-13) and mass spectral analysis. Gelation properties of the synthesized molecules in different solvents and oils were studied and gelation was observed with minimum Critical Gelator Concentration (CGC) of 0.8% (w/v) in benzene. The free hydroxyl group of the sugar moiety, benzohydrazide and three alkyl chains present in all these compounds afford the collective driving forces for gelation. Phase-Selective Organo-Gelators (PSOGs) are molecules that can gel the oil selectively from the biphasic combination of oil and water and it is one of the good candidates for recovering oil in case of oil spill. It is observed that these gelators can be used as solid particles on a biphasic system consist of oil and water. It solidifies the oil selectively which can be taken out by means of the physical process. FT-IR and UV-Vis spectroscopy suggest that the driving forces for the gelation are hydrogen-bonding, pi-pi stacking and van der Waals interaction. The gels were studied using FE-SEM, DSC and rheological techniques. FE-SEM analysis shows that the formation of thin fibers and large wrinkle like aggregate structure in the gel state is due to the presence of different weak molecular interactions. The phase selection and gel-sol transition properties of these molecules confer their ability to absorb and release dyes with high efficiency.