Composite Magnetic Material for Oil Removal from Water: Pollution Cleanup of the Future?

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Home / Composite Magnetic Material for Oil Removal from Water: Pollution Cleanup of the Future?

Oil spill can pose a threat to the environment. Phot by Public Domain Images.

Water pollution is a real problem, and removing pollutants, such as oil, from bodies of water is the aspiration of many environmental scientists.

Researchers have now developed a new material that can remove oil contaminants from water.

The new material is a composite made of polyurethane foam, polytetrafluoroethylene spheres, and iron oxide nanoparticles – it is magnetic, so clean-up crews can easily remove it from polluted areas, once the clean-up is complete, by attracting the material with a magnet.

Oil and Fuel Pollution

Pollution from oil, fuels, and/or their derivatives has become an increasing problem in recent years. Accidents causing oil and fuel spills into sea waters can have devastating consequences on the environment, in both the short and long term. For this reason, it is important to develop methods and/or substances which can purify the polluted waters quickly and effectively.

Water-Oil Separation

One method of cleaning waters from oil pollution is through the use of soaps/surfactants, which can dissolve the oily molecules. Alternatively, the oily pollutants can be removed using a material which can separate the oil(s) from the water. Such material should be very hydrophobic (water-repellant) and very oleophilic (attracted to oil). In this way, the water phase could be repelled; the oil phase, on the contrary, could be adsorbed (stuck to the surface of the material) and separated from the water.

Innovative Composite Cleaning Material

A new material, based on the water-oil separation principle, has been developed by the researchers of the Italian Institute of Technology (Istituto Italiano di Tecnologia, IIT, Lecce and Genova, Italy). The results of their study were published in ACS Nano journal.

The material was obtained using commercially-available polyurethane (PU) foams. They were modified into composite materials with microspheres of polytetrafluoroethylene (PTFE) and nanoparticles (NPs) of iron oxides.

Composite Preparation

The PTFE microspheres and iron oxide NPs were introduced into the PU foam structure in different ways.

An electrostatic triboelectric charging process was used for the PTFE microspheres: a layer of spheres was spread on the surface of the foam, and subsequently an electrostatic effect was created by rubbing a metallic palette against the foam surface.

To introduce the iron oxide NPs, on the other hand, the foam was added to a NPs- containing solution (in toluene); in this way the NPs could be transferred into the foam network by capillary action.

Several composite materials were prepared, modifying the PU foam with PTFE only, NPs only, and with both PTFE and NPs. In this last case, two different deposition sequences were considered, adding either the PTFE microspheres or the iron oxide NPs first.

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