Core-shell composite nanoparticles with magnetic and temperature dual stimuli-responsive properties for removing emulsified oil

Core-shell magnetic and thermosensitive composite nanoparticles, named as M-DMEA, were prepared by grafting polyoxyallcylated N,N-dimethylethanolamine onto magnetite (Fe3O4) nanoparticles. A series of characterizations were performed to figure out the properties of the as-prepared M-DMEA. The results reveal that the M-DMEA is superparamagnetic and has irregular shape with a core-shell structure. The flocculation performance of M-DMEA in oily wastewater produced from flooding (OWPF) treatment was investigated for the first time. It was found that the M-DMEA could separate emulsified oil droplets from OWPF rapidly under an external magnetic field with high oil removal (92.3% at the dosage of 2.5 g/L) at 65 degrees C. Moreover, due to its excellent magnetic response, the M-DMEA can be collected and recycled for another 3 cycles. Factors affecting the flocculation performance were discussed in detail. It is anticipated that as-prepared M-DMEA might find its potential application in practical oily wastewater treatment. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.