Researchers create a reusable sponge made of wood that selectively absorbs oil.
When crude oil or refined oil products are released into the water or on land it is referred to as an oil spill. Oil spills are a disastrous form of pollution causing damage to the environment’s air, land, water, and living organisms. Their consequences affect our world socially, economically, and environmentally. Man-made factors and tectonic events are the causes responsible for such a catastrophe.
Water is contaminated with silicone oil (dyed red) and the newly developed sponge material is swept over the surface to absorb the oil layer; the oil-saturated sponge floats in the dish and can easily be picked up out of the clean water. Credit: Justin Weibel
When there is a spill it is extremely difficult to clean up once it has emulsified, meaning once it has broken up into little droplets and dispersed in the water. That is why it is crucial to clean up the spill as quickly as possible, while it has just happened and is a still film floating on the top of the water. However, if that is not possible and it has emulsified (or even if it hasn’t yet) there is a great potential that these wooden sponges will be the solution to spillage.
The wooden sponge was created through the modification of a low-density material often used in crafting models called balsa wood. Scientists used chemicals to break down the wood’s cell-walls and remove the polymers, lignin, and hemicellulose, all the things that make it strong and rigid. What resulted was a material that was highly porous with a density just one-third that of the original balsa wood. This new material was then finished with a coating to repel water but that could readily absorb oil.
Credit: American Chemical Society
Tests revealed that these sponges could soak up anywhere between 16-41 times their weight in oil. Therefore, they could be used as a filter to continuously remove oil from a solution or as a sponge to soak up oil. Used in this way, it can be wrung out and reused more than ten times.
As of now, this experiment proves that the wooden sponge is a successful solution on a small-scale. More tests need to be done to see if this technology can work on a grand scale.