A new technology that is easy to manufacture and uses commercially available materials makes it possible to continuously remove oils and other pollutants from water, representing a potential tool for environmental cleanup.
The material is shown to be superhydrophobic and superoleophilic, meaning it rejects water while absorbing oils. It is made using melamine sponges, an ultra-low-weight, porous material found in various products including household cleaning pads and insulation materials.
The researchers modified the melamine sponge by dipping it into a solution containing a small amount of silicone rubber called PDMS and the solvent hexane, resulting in an extremely thin coating that repels water while allowing oil to be absorbed into the sponge.
"The reason we're excited about this is that it is manufactured using a very inexpensive one-step process to coat the melamine sponges, and the material can be reused many times," said Distinguished Professors of Mechanical Engineering. "We believe this can be readily adopted for the cleanup of oil spills and industrial chemical leaks."
Other technologies under development that incorporate superhydrophobic and superoleophilic properties are either expensive, difficult to scale up, or require the use of exotic materials such as carbon nanotubes and graphene.
"Oil spillage from industrial sources has caused severe damage to the environment," Chen said. "The conventional methods used to clean up oils and organic pollutants are slow and energy-intensive. The development of absorbent materials with high selectivity for oils is of great ecological importance for removing pollutants from contaminated water sources."
Findings show the sponge material has an absorption capacity of 45-75 times its own weight, which is comparable to other more exotic materials under development.