Laser-treated cork proves effective and sustainable for oil spill cleanup, quickly separating oil from water without chemical dispersants. Credit: SciTechDaily.comOil spills are deadly disasters for ocean ecosystems. They can have lasting impacts on fish and marine mammals for decades and wreak havoc on coastal forests, coral reefs, and the surrounding land. Chemical dispersants are often used to break down oil, but they often increase toxicity in the process.
To remove oil from water, the authors used cork treated by a fast-pulsing laser method that removes some oxygen from the material, increasing the relative carbon and making it more water-repelling and oil-attracting. Laser treatment also alters the structure of the cork: When viewed at the nanoscopic level, the material has deep grooves, which increase the total surface area of the cork and allow it to trap sunlight and warm the oil, making the oil easier to collect.
Cork comes from the bark of cork oak trees, which can live for hundreds of years. These trees can be harvested about every seven years, making cork a renewable material. When the bark is removed, the trees amplify their biological activity to replace it and increase their carbon storage, so harvesting cork helps mitigate carbon emissions.The authors tested variations of a fast-pulsing laser treatment to achieve the optimal balance of characteristics in the cork that can be achieved at low cost.
As a result, the cork collects the oil without absorbing water, so the oil can be extracted from the cork and possibly even reused.