Freeze-dried foam absorbs CO2

Scientists have developed a reusable foam that can absorb carbon dioxide, potentially helping in the fight against global warming.

With climate change an ever-increasing concern, scientists have been working to develop new materials that can aid the fight by ridding the environment of pollutants, such as carbon dioxide, that contribute to global warming. We have recently seen innovative pollution-fighting materials that range from an absorbent bikini that may help rid the ocean of pollutants to a smog vacuum that can turn pollutants into jewellery. Now, materials scientists in the Ajayan Research Group at Rice University, led by Dr. Pulickel Ajayan, have create a lightweight foam that absorbs CO2.

The foam is made from two-dimensional sheets of hexagonal-boron nitride (h-BN). Flakes of h-BN are combined with polyvinyl alcohol and freeze-dried to create flat sheets of the absorbent material. According to researchers, the one-step manufacturing process is fully scalable. The porous foam is capable of absorbing up to 340 percent of its own weight in carbon dioxide. The CO2 gas can be evaporated out of the foam, which can then be reused. When coated with the polymer PDMS, the h-BN foam can be used as a shield from lasers, allowing it to be used in biomedical and electronics applications.

The researchers would ultimately like to be able to manipulate the size of the materials’ pores in order to use it to absorb specific materials, such as separating oil from water. The research was funded by the Air Force Office of Scientific Research and appears in the American Chemical Society journal ACS Nano. What other types of materials might one day absorb greenhouse gases from the environment?