Synthesis and application of bisurea derivatives: Effect of structural differences on the gelation properties

Abstract

A series of bisurea derivatives were synthesized and applied as low molecular weight organogelators to gelate different organic solvents. The efficiencies of the synthesized derivatives, based the variety of the solvents gelated and the minimum concentration needed for gelation of a solvent at room temperature were investigated as a function of their structural differences. Among them, 1,1′-(hexane-1,6-diyl)bis(3-octadecylurea) (compound 1a) showed the best performance as an organogelator with MGC value of 3 mgmL-1 in nitrobenzene and the obtained gel was characterized by various methods (FT-IR spectroscopy, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and rheology technique). The results of SEM analysis showed that the nature of the solvent affected the process of gelation and minimum gel concentration. Also, compound 1a was directly used as a solid to separate oil products from oil/water mixture. The results demonstrated the efficiency of this compound in solidifying oil spills due to the fast oil gelation, convenient and complete oil elimination, easy oil recovery and reusability of the gelator. © 2021 Elsevier Ltd.