Freeze-dried boron nitride foam can adsorb large volumes of carbon dioxide from the atmosphere according to research from a team at Rice University. The foam comprises layer upon layer of "two-dimensional" hexagonal boron nitride sheet. The addition of polyvinyl alcohol (PVA) to the preparation makes a robust material that does not disintegrate in liquids. Team leader Pulickel Ajayan suggests that the material can be fine tuned for particular applications, such as exhaust scrubbing or air filters. In computer simulations, the foam can adsorb 340 percent of its own mass in carbon dioxide, the team reports in the journal ACS Nano.