Preparation of hydrophobic macroinimer–based novel hybrid sorbents for efficient removal of organic liquids from wastewater

Herein, the synthesis of hydrophobic macroinimer–based hybrid sorbents and their use in the removal of organic solvents from wastewater is explored. Polydimethylsiloxane (PDMS), 4,-4′-azobis-4-cyanopentanoyl chloride (ACPC), and methacryloyl chloride were reacted via bulk condensation polymerization to synthesize the macroinimer. The organogel systems were then prepared with macroinimer using different acrylic monomers of methyl acrylate, ethyl acrylate, and butyl acrylate without any additional crosslinker and initiator. The structural properties of the obtained final products were characterized by FT-IR, 1H-NMR, and TGA. The effect of alkyl chain length and macroinimer moieties in the organogel networks, as well as the swelling capacities of the prepared gels, was evaluated for different organic solvents and oils. The maximum solvent absorbencies of macroinimer-based organogels were determined as 85.3%, 100.9%, 1422.1%, 1660.0%, 3809.3%, and 5032.2% for diesel oil, gasoline, acetone, benzene, tetrahydrofuran (THF), and dichloromethane (DCM), respectively. Furthermore, adsorption-desorption kinetics, selective absorption from oil/water mixtures, temperature effect on the absorption capacity, and reusability tests were investigated. Obtained results showed that the prepared organogels possessed high swelling, efficient absorption capacity, and good oil separation performance in the removal of organic solvents from wastewater. The temperature-dependent absorption study shows no significant change in absorption capacity. Thus, the prepared macroinimer-based organogels in the present study demonstrate potential as prospective sorbents for organic pollutant cleanup from wastewater.