Hydrophobic Eutectogels for the Removal of Contaminants of Emerging Concern from Water

Abstract

Five hydrophobic eutectic solvents based on menthol and thymol were prepared and incorporated into a poly(ethylene glycol) diacrylate (PEGDA) network to form eutectogel membranes. The two most promising eutectogels were further optimized by adding ethyl hexylacrylate (HA) to the eutectogel formulation to improve the compatibility between the eutectic solvent and polymer network and to enhance the water resistance of the resulting membranes. Thermal analysis confirmed the successful formation and integration of eutectic solvents within the polymer network. Rheological studies demonstrated the rubber-like behavior of the prepared hydrophobic eutectogels, with menthol-based variants exhibiting superior mechanical properties. Finally, sorption experiments were conducted using the optimized octanoic acid:menthol PEGDA-HA eutectogel to evaluate its efficiency in removing various contaminants of emerging concern (CECs), including diclofenac, iopromide, cefazolin, bisphenol A, and dichlorophenol. The results revealed high sorption capacities for bisphenol A (3213 mg⋅kg−1) and dichlorophenol (2981 mg⋅kg−1), followed by diclofenac (1490 mg⋅kg−1), whereas minimal sorption capacities were observed for iopromide and cefazolin. Overall, this study demonstrates the potential of hydrophobic eutectogels as efficient and tunable materials for water purification, paving the way for their application in the environmental remediation of different emerging pollutants related to global change and human activities.