Adsorptive Removal of 1,2-Dichloroethane Using Novel Oleogel Adsorbents: Synthesis Strategy and Adsorption Mechanism Insight

Abstract 1,2-Dichloroethane (DCE) is a widely used, highly volatile, and lipophilic industrial solvent. As a chlorine-containing volatile organic compound (VOC), DCE emissions pose significant risks to human health and the ecological environment. Adsorption is considered an economical and environmentally friendly method for eliminating air pollutants. In this study, novel Oleogel adsorbents were prepared via self-assembly and polymeric cross-linking mechanisms, using 12-hydroxystearic acid (12-HSA) and ethyl cellulose (EC) as gelators, and rapeseed oil (RO) and dioctyl adipate (DOA) as base oils. A series of oleogels were fabricated by varying the type and dosage of gelators, and their structures, physicochemical properties, and DCE adsorption performance were systematically characterized. The DCE adsorption behavior and mechanism were investigated through dynamic adsorption experiments, multimodel kinetic fitting, and spectral analysis at multiple temperatures. The results showed that the 10 wt % 12-HSA/DOA Oleogel achieved a DCE adsorption capacity of 154.4 mg g–1 at 25 °C and reached 201.9 mg g–1 at 15 °C, which is comparable to those of previously reported adsorbents. Characterization and adsorption experiments demonstrated that the adsorbent exhibited a stable three-dimensional crystalline architecture, excellent oil retention (up to 98% after centrifugation), and favorable thermal stability below 150 °C. Meanwhile, DCE adsorption on Oleogel adsorbents involves significant intermolecular interactions (e.g., dipole–dipole and hydrogen bonding) rather than a purely physical process, and their surface is enriched with exposed functional groups, such as carbonyl and carboxyl groups. Further analysis indicated that the base oil was the dominant factor governing DCE adsorption performance, and the gelator type was the decisive factor influencing crystal morphology development. Notably, the contact angle of samples prepared from ethyl cellulose and dioctyl adipate reached 95.6°, suggesting potential for use in high-humidity environments.