Artificial 'foam' absorbs heavy metals

This spongy material will absorb heavy metals in the same solution as a sponge, which promises to be useful in removing pollutants from the water. The product is the invention of American scientists.

This material is a gas gel - a solid form made from a gel where most of the liquid has been replaced by gas.

(Photo: iStockphoto) "It's a new energy gel made from material similar to semiconductors," Professor Mercouri Kanatzidis, from Northwestern University in Illinois, said.

Traditional gas gels, made from silicon and carbon, have been around for decades. They are white, colorless and do not absorb light. Many of them are oxides.

Unlike them, Kanatzidis made gas gels containing heavier, sulfur or selenium compounds in place of oxygen, making them unique. They absorb light and can be changed from one form to another.

Kanatzidis and his colleagues put the new gel in a solution containing smaller metal ions and larger, more toxic metal ions such as mercury ions. As a result, the gel absorbed all the mercury from the solution as well as some organic compounds.

"It is very much like a sponge, only the sides of this sponge are very fond of sulfur atoms in the solution, which Mercury likes to attach to sulfur."

T. An