Phenoxy‐Alkyl Maleates as Phase‐Selective Organogelators for Gelation of Edible Oils

Abstract

Phase selective gelation may solve environmental problems such as water pollution and fire accidents during oil storage, a major problem for aquatic bodies. The objective of this work is to synthesize a series of phenoxy‐alkyl maleates (n‐PAM) oleogelators with homologous alkyl chain lengths for efficient phase selective gelation. The n‐PAM molecules are found to form oleogel in various edible oils among which sunflower oil shows best gelation. The gelation behavior increases with an increase in alkyl chain length of the n‐PAM gelators as observed from their low minimum gelation concentration (MGC) values. Oleogels thermal stability is examine through tube inversion method and differential scanning calorimetry (DSC). The rheological studies suggest that the oleogel of sunflower oil is mechanically stable and show typical viscoelastic properties. The field emission scanning electron microscopy (FE‐SEM) study of the gels shows sheet‐like morphology. Furthermore, the n‐PAM gelators exhibit quick phase selective gelation of edible oils at low MGC. Both the edible oil and gelator are quantitatively regained from recovered oleogel by employing the vacuum distillation. It is believed that these n‐PAMs could aid in reducing the environmental impacts of oil spills.Practical Applications: The phenoxy‐alkyl maleates gelators present in the MS show gelation ability in various edible oils at low minimum gelation concentration. These molecules also form efficient phase selective gelation with edible oils. Both oil and gelator can be recovered through vacuum distillation and gelator can be reused multiple times. Thus, all these advantages strongly point that out their bright future, in particular in edible oil spill recovery, could aid in reducing the environmental impacts from oil spills.Herein, the synthesized phenoxy alkyl maleate derivatives are reported as separators of edible oil from the oil‐water biphasic mixture. Initially, the gelator is solubilized in the biphasic mixture by heating. Later, gelation ability is observed by tube inversion method. From the phase selective gel, oil and gelator are separated through a distillation method. The recovered gelator can be reused in oil recovery process. This application may find use in oil recovery from waste plant of edible oil industries.