Oleo Sponge

Organization: Argonne National Laboratory
Year: 2017

Oleo Sponge is a novel absorbent for cleaning up oil spills from water, based on low-cost materials and processing. Oleo Sponge can absorb up to 90 times its own weight in oil, is reusable and can collect oil both above and below the water’s surface. Oleo Sponge is created by chemically treating a polymer foam such as polyurethane. As manufactured, polyurethane foam is not effective for removing oil from water. This is because the surface of polyurethane is neither oleophilic (oil-attracting) nor hydrophobic (water-repelling). Consequently, when polyurethane foam is immersed in an oil/water mixture, it will absorb both substances more or less equally. In contrast, Oleo Sponge is simultaneously highly oleophilic and highly hydrophobic, so that it rapidly and selectively absorbs oil from an oil/water mixture. These properties are imparted by performing a two-step surface chemical treatment. In the first step, the foam is impregnated with an ultra-thin, inorganic coating using sequential infiltration synthesis. This coating “primes” the surface for the next step. In the second step, the resulting surface is functionalized with an oleophilic monolayer using silanization, a self-limiting surface chemical reaction.