Available Technology

BSA 14-23: Superhydrophobic Sponges as Efficient Oil and Organic Liquid Absorbents

Oil spills have become an environmental problem due to the growth of offshore oil exploration, production and transportation. There are several methods that have been used to clean up oil spills such as chemical dispersants, water skimming, and using absorbent materials. Although skimming is the most common method for cleaning large spills, this method is time consuming, expensive, and poorly separates oil and water. Chemical dispersants can be used to break up oil slick into droplets that can be easily dissipated in water, but the mixture of oil and dispersants can be toxic and damage marine ecosystems. Thus, the use of oil sorbents can be an effective method to ease oil collection and sorbents have a high capacity for removing oil from a targeted site. The present invention provides a simple, cost-effective method to fabricate robust superhydrophobic sponges with excellent oil sorption capacity and exceptional recyclability.
Patent Abstract: 
A method to fabricate superhydrophobic sponges by chemically modifying the surface of sponge skeletons via a solution-immersion process. This process comprises of the silanization of commercially available sponges, such as melamine, by reacting secondary amine groups on the surface of the sponge skeletons with alkylsilane compounds. This will inherently form monolayers that are able to self-assemble on the surface of sponge skeletons, resulting in the chemical modification of the surface properties of the sponges. The resulting modified sponge is stable and its properties can be easily tuned from being hydrophilic to superhydrophobic. The chemical bonds between surface and sponge skeleton remain unaffected during oil absorption-squeezing make them reusable for repetitive cycles.
The present fabrication approach is fast, simple, inexpensive, widely applicable, and scalable in comparison to previous processes. The superhydrophobic sponges may have a sorption capacity greater than 160 times its own weight; it's recyclable with retention for more than 90% after 1000 cycles; and the coating is not easily detached from the sponge skeleton. Moreover, the invention is capable of absorbing a range of organic solvents and oils including acetone, butanol, toluene, THF, DMF, chloroform, diesel, motor oil, machine oil, biodiesel, and mineral oil.
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