Video: Coated sponge can absorb oil from frigid watersMarie Donlon | March 18, 2021
Scientists from Imperial College London and the University of Toronto have developed a sponge that is capable of cleaning up oil spills in Arctic waters with temperatures as low as 5° C.
Using previously developed sponge technology, the team of scientists created a coating that enables the sponge to recover oil droplets from waters with temperatures below 38° C — a temperature at which oil crystallizes and becomes viscous around its edges.
The paraffin-like coating features a chemical structure similar to oil, which created a mutual attraction between the coating surface and the oil surface. Through a process called wax-wetting, wherein one fluid is used to displace another, the sponge is rinsed with a non-toxic solvent called heptol, which displaces the oil droplets. According to the scientists, both the sponge and the oil droplets can be reused.
In the lab, the coated sponge absorbed oil droplets from water in the temperature range of 5° C to 40° C, removing 90% to 99% of contaminants in under three hours.
Current technologies for removing oil droplets from ultra-cold waters are generally energy intensive, expensive and ineffective.
The coated sponge is detailed in the journal Science Advances and additional information is available in the accompanying video that appears courtesy of Imperial College London.