Materials collect water from the air

Abstract

Every evening during the summer of 2020, Xingyi Zhou went up to the roof of her lab building at the University of Texas at Austin to check on two plastic boxes containing radish plants. Plants in one of the boxes languished, while those in the other flourished, even though both grew in sand that Zhou and her colleague Fei Zhao collected from an Austin park. The key difference was a ground-up slab of a hydrogel mixed in the sand of one of the boxes. The tiny grains of hydrogel absorbed moisture from the cool, humid night air. In the mornings, the hydrogel gradually warmed up under the heat of the sun and released the water it had absorbed overnight, generating a humid, healthy environment for the plants ( ACS Mater. Lett. 2020, DOI: 10.1021/acsmaterialslett.0c00439 ). Materials like this UT Austin hydrogel could someday help mitigate the world’s water woes. Four