As microplastic contamination and the lack of drinkable water worsen, finding efficient technologies to filter and desalinate seawater becomes increasingly vital. A novel airgel, fabricated from egg whites, shows great promise.

An egg-citing concept

Professor Craig Arnold of Princeton University came up with the idea at a faculty meeting when thinking about the bread of the sandwich he was eating. He believed that the internal structure of bread would function effectively if water were integrated into the filtering aerogel, so he instructed his lab crew to develop various bread recipes with the added carbon.

Initially, none of the bread aerogels adequately replicated the structure, so the scientists depleted the material until only egg whites and a small quantity of carbon remained. Arnold stated that the proteins in the egg whites were responsible for forming the desired shapes.

How effective are egg white filters?

According to reports, the current version of the airgel eliminates salt and microplastic particles from saltwater with 98 and 99 percent effectiveness, respectively. It’s manufactured by simply freeze-drying an egg’s protein/carbon mixture and then heating it to 900 C (1,652 F) in an oxygen-free atmosphere. The outcome is a material with a structure resembling bread, composed of linked carbon fiber strands and graphene sheets.

The airgel is said to be significantly more effective than activated carbon filters, and unlike reverse osmosis systems, it does not require energy; gravity is used to draw in seawater. There is presently no data regarding the rate of water filtration.

It should be emphasized that although eggs are very inexpensive and abundant, their usage to manufacture aerogel would reduce the food supply. However, this should not be a concern, as it has been discovered that similar commercially available proteins function in the same manner.

Other potential uses for the novel airgel

Arnold and his coworkers are currently striving to expand the production method. Eventually, it is believed that airgel can be utilized not just for water filtering, but also for energy storage, soundproofing, and thermal insulation.

A paper that was recently published in the journal Materials Today describes the research.

Source study: Materials Today— Egg protein-derived ultra-lightweight hybrid monolith aerogel for water purification