A tertiary amine group-based organogelator with pH-trigger recyclable property

Organogelators have received extensive attention in the recovery of leaked organic solvents or oil spills. However, due to the interactions of organogelators with the organic solvents/oil, the separation and recovery of organic solvents/oil and organogelators from organogels is difficult. In this study, we have developed an organogelator with pH-triggered recyclable property, realizing the recovery of oil and organogelator. The organogelator (HSA-N) is synthesized with 12-hydroxystearic acid (HSA) and 3-dimethylaminopropylamine by an amidation reaction. Here, HSA-N can gelate several organic solvents and fuel oils at a low concentration (less than 1 wt%), which is induced by the strong hydrogen bond interaction and van der Waals forces demonstrated by X-ray diffraction (XRD) and infrared spectroscopy (IR). As HSA-N can reversibly transform between hydrophilicity and hydrophobicity by regulating pH, the separation and recovery of organic solvents/oil and organogelator can be achieved at room temperature. Herein, organogelators with pH responsiveness make it promising to recover organic solvents/oil and organogelators from organogels at room temperature.