Although the application of nanotechnology for oil spill cleanup is still in its nascent stage, it offers great promise for the future. In the last couple of years, there has been particularly growing interest worldwide in exploring ways of finding suitable solutions to clean up oil spills and deal with industrial oily wastewater through use of nanomaterials. Key for the success of these materials is a high separation capacity, with resistance to oil fouling, and that are easily recyclable.
Oil/water separation is an interfacial challenge, and novel materials designed to possess special wettability have different interaction and affinity for oil and water, thus can realize the separation.
“Until now, researches in this field all focus on materials with both hydrophobic and oleophilic properties,” Lin Feng, an associate professor in the Department of Chemistry at Tsinghua University in Beijing, explains to Nanowerk. “Those materials realized filtration or absorption of oils from water selectively and effectively – the so-called ‘oil-removing’ type of materials. However, the oil-removing type of materials is easily fouled even blocked up by oils because of their intrinsic oleophilic property. The adhered oils, especially high-viscosity oils, seriously affect the separation efficiency after using for limited number of times. In addition, oils adhered or absorbed are hard to remove, which result in secondary pollution during the post-treatment process as well as a waste of both oil and oleophilic materials.”
In new work, Feng and a team os scientists from Beijing National Laboratory for Molecular Sciences and Beihang University, fabricated a novel superhydrophilic and underwater superoleophobic hydrogel coated mesh. As they reported in the August 17, 2011 online edition of Advanced Materials (“A Novel Superhydrophilic and Underwater Superoleophobic Hydrogel-Coated Mesh for Oil/Water Separation”), this new material can selectively separate water from oil/water mixtures such as vegetable oil, gasoline, diesel, and even crude oil/water mixtures effectively (more than 99 %) and without any extra power.