One-Step Synthesis of Polyethylenimine-Coated Magnetic Nanoparticles and its Demulsification Performance in Surfactant-Stabilized Oil-in-Water Emulsion |
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Authors: | Hongting Zhao Chuan Zhang Dongming Qi Dong Zhang |
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Institution: | 1. Institute of Environmental Materials and Applications, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou, China;2. Engineering Research Center of Eco-Dyeing and Finishing of Textiles of Ministry of Education, Zhejiang Sci-Tech University, Hangzhou, China |
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Abstract: | In this study, polyethylenimine (PEI)-coated Fe3O4 magnetic nanoparticles (MNPs) were successfully synthesized via a one-step, solvo-thermal method. The synthetic PEI-coated MNPs were characterized by using multiple techniques and their demulsification efficiencies were evaluated in surfactant-stabilized, oil-in-water emulsions. The results showed that the synthesized MNPs successfully adsorbed to the emulsion’s O/W interfaces and, consequently, the oil droplets could be rapidly destabilized under an applied magnetic field. It was found that the demulsification efficiency was enhanced with the increased particle dosage. The opposite effect was found with the increase in pH value and surfactant concentration. The presence of electrolytes facilitated oil removal, presumably by reduction of the electrostatic repulsion or by altering the hydrophobicity of the MNPs. Recovery experiments at various pH levels indicated that the PEI-coated MNPs could be reused for up to ten times without significant reduction in demulsification efficiency. Altogether, the results suggested that the PEI-coated MNPs could provide a simple but powerful tool to remove emulsified oil from aqueous systems. |
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Keywords: | Magnetic nanoparticles polyethylenimine oil-in-water emulsion demulsification recyclability |
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