Salting-in Effect of Zwitterionic Polymer Hydrogel Facilitates Atmospheric Water Harvesting

Hygroscopic salt-hydrogel composite sorbents have attracted increasing attention for atmospheric water harvesting (AWH) applications but suffer from the salting-out effect. To this end, this work, for the first time, discovers that the salting-in effect possessed by a zwitterionic hydrogel is able to facilitate water vapor sorption by the hygroscopic salt under otherwise the same conditions. For demonstration, zwitterionic hydrogel of poly-[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (PDMAPS) was synthesized, and the hygroscopic salt of LiCl was embedded into PDMAPS to produce the salt-hydrogel composite. LiCl salt not only endows the sorbent with high water vapor sorption capacity but…

• KA
  King Abdullah University of Science and Technology