Cleaning Up Oil Spills With Two-Faced Magnets

Researchers in China have developed a magnetic particle that can separate oil particles from water rapidly and efficiently.

AsianScientist (Jul. 9, 2018) – Chinese researchers have developed magnetic particles for oil-water separation, which could be useful for cleaning up oil spills. They published their findings in Advanced Functional Materials.

Oil pollution is a global challenge. In practice, oils are usually classified as floating oils, dispersed oils, surfactant-stabilized oil droplets and surfactant-free micro-scaled tiny oil droplets. Scientists have long sought methods to effectively separate the various types of oils from water. However, micro-scaled oil droplets with diameters less than 20 μm are very stable in water, making them hard to clean up.

In the present study, researchers from the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences developed Janus particles—particles with two different properties on their surfaces—that can rapidly and efficiently separate micro-scaled tiny oil droplets from water.

They synthesized the oil-binding particles using a method known as emulsion interfacial polymerization, which resulted in Fe3O4 nanoparticles. When these Janus particles were added to an oil-in-water emulsion and shaken for one minute, the originally stable emulsion rapidly formed layers.

The upper oil phase was rapidly attracted towards a magnet. The researchers obtained >99 percent separation within two minutes. They also found that the oil-binding surface of their Janus particles was beneficial for capturing a large number of tiny oil droplets to make them coalesce. Finally, like surfactant molecules, these Janus particles could adsorb at the interface of large oil droplets to stabilize them.

These particles are also good candidates for cleaning up industrial wastewater and water purification, the researchers said.

The article can be found at: Song et al. (2018) Hydrophilic/Oleophilic Magnetic Janus Particles for the Rapid and Efficient Oil–Water Separation.


Source: Chinese Academy of Sciences; Photo: Pixabay.
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