Harvesting of Atmospheric Water Using Polymer-Based Hybrid Hydrogels

Atmospheric water harvesting (AWH) is an important parallel or supplemental freshwater production technique to liquid water resource-based technologies due to the availability of moisture resources regardless of location and the possibility of realizing decentralized applications. Recent developments to regulate the characteristic features and nanostructures of moisture-harvesting materials demonstrate new opportunities to improve device efficiency. Focusing on the design of water harvesting materials and the optimization of the overall system, this review sums up the most recent developments in this area and presents prospects for the future development of AWH. An overview of the processes involved in water sorption by various sorbents and the characteristics and functionality of the polyaniline-based hydrogels developed for AWH is given. Newly reported hydrogel sorbents used for AWH are evaluated, focusing on their benefits, drawbacks, and design methodologies. Several AWH-specific water harvesters are described and the impact of the system's mass and heat transfer on its operational effectiveness is explored. Finally, potential roadmaps for the development of this technology are detailed and the challenges in this subject from both a basic research and practical application perspective are discussed.