An ultra-hygroscopic polymer for high-efficiency dehumidification

Desiccant-coated heat exchangers (DCHEs) offer the potential to effectively remove moisture from the environment. However, the low adsorption capacity, slow kinetics, and high energy consumption of existing desiccants limit the dehumidification efficiency of DCHEs. Thus, we synthesize an ultra-hygroscopic polymer by introducing lithium chloride into a curdlan matrix to form LiCl@Cur and developed a high-efficiency LiCl@Cur-coated heat exchanger (CLCHE). This developed LiCl@Cur has remarkable sorption capacities of 2.65 g/g and fast kinetic 1.84 × 10−4 s−1 at 30°C/30% relative humidity (RH). Our work shows that the dew point of humid air can drop by up to 30° through only a 15 mm CLCHE channel. We also demonstrate that curdlan-based desiccant can be used for dehumidification, and its ultra-hygroscopic performance enables efficient deep dehumidification, which has bright prospects for applications in fields such as electrode production and green building.