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, work, first time, discovers that salting-in effect possessed by a zwitterionic hydrogel is able to facilitate vapor sorption hygroscopic salt under otherwise same conditions. For demonstration, of poly-[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (PDMAPS) was synthesized, and LiCl embedded into PDMAPS produce composite. not only endows sorbent with high capacity also facilitates dissociation self-association between cationic anionic groups PDMAPS. This evaluated confirmed experimentally via density functional theory (DFT) calculation. The renders matrix enhanced swelling capacity, leading sorbent’s AWH performance. With photothermal component CNT integrated sorbent, fully solar energy-driven process demonstrated outdoors. study provides important guidance design hydrogel-based sorbents.