In this extreme closeup, the clay aerogel's "house of cards" structure is evident. The gaps between the layers of clay were created by freeze-drying the sample. Coating the aerogel's surfaces with a polymer will help retain its spongy shape. Credit: Suneel Bandi/Case Western Reserve University

Freeze drying causes gaps to form between the layers of clay. Credit: Suneel Bandi/Case Western Reserve University

The sustainability of a product often is found in applications not originally considered. A case in point is AeroClay, a product developed by Case Western Reserve University professor David Schiraldi.

AeroClay is a patented foamlike and environmentally friendly clay-based polymer. AeroClay materials feel and act like foam, without injection of gas bubbles or environmentally unfriendly CFCs.

The clay aerogels are produced in a wide variety of shapes using a freeze-drying technique. If the aerogel is later fired to 800ºC, it undergoes a chemical transformation. Depending on additives, the AeroClay can become a hard, lightweight ceramic, a bendable material, a superlightweight magnet, an electrical conductor, or a catalyst.

Schiraldi’s group recently combined clay, water and milk protein (casein) found in wastewater from the cheese-making process. The result was a high-temperature polymer that withstands temperatures to 300ºC. The new material has the potential to insulate pipes that carry high-temperature materials throughout refineries.

They also experimented with the seaweed protein alginate, but the casein resulted in a better product.

Schiraldi told the Cleveland Plain Dealer that he’s formed a company, AeroClay Inc. to try to market new AeroClay products. One he mentioned is a light-weight cat litter.

“Grandma goes to the store and has to carry this 30- or 40-pound tub back,” Schiraldi told the newspaper. “What if you could get the same function, and instead of 30 or 40 [pounds], it was 3 or 4? Would you pay an extra dollar for that tub? A lot of people would.”