More science with wood: this time a sponge made from wood that selectively absorbs oil.

 

Scientists have traditionally attempted to clean up oily water with gravitational separation, burning, and bioremediation. But these methods were either inefficient, bad for the environment, or cost too much.

 

The sponge, created by Chinese researcher Xiaoqing Wang and his team, is made by treating natural balsa wood with chemicals that removed lignin and hemicellulose, leaving behind a cellulose skeleton. The remaining highly porous structure was then coated with a hydrophobic coating that attracted oil and repelled water.

 

When placed in a mixture of water and silicone oil, the wood sponge removed all of the oil, leaving clean water behind. Depending on the oil tested, the sponge absorbed 16 to 41 times its own weight, which scientists say is equal to or better than most other reported absorbents.

 

After soaking up oil, the sponge can be simply squeezed out like a normal sponge. It is capable of enduring at least 10 cycles of absorption and squeezing.

 

It's not known what will become of this technology. Researchers received funding from the National Key Research and Development Program of China and the National Natural Science Foundation of China.