Hierarchically Soft Porous MOF-Polymer Monolith for Fast and Large-Scale Moisture Buffering

The influence of high indoor humidity on building and equipment safety and human health has led to an urgent demand for the development of high-performance dehumidification technologies. To simultaneously satisfy the requirements of easy shaping, nontoxicity, and low energy consumption for indoor dehumidification, an effective strategy involving the combination of non-toxic microporous materials with a shaping matrix equipped with switching functionalities via a synergetic porous interface can be used. This study proposes an in situ interface-controlled growth method to produce a novel hierarchically porous hydrogel adsorbent for indoor dehumidification by combining metal-organic frameworks (MOFs) with a poly(N-isopropylacrylamide) (PNIPAM) thermoresponsive hydrogel matrix. The obtained composite hydrogel monolith, ThermoGel-23, exhibits a moisture uptake capacity of 1.64 g·g^-1, high adsorption rate, and desorption activation energy as low as 31.0 kJ·mol^-1, meeting the requirements of indoor adsorption dehumidification. Combining experiments and simulations, we elucidated the transport pathways of water clusters within the hierarchical pores and highlighted the essential role of porous structure and thermal response in enhancing both adsorption and desorption. This work demonstrates the potential of MOF-polymer composites as efficient, scalable desiccants, paving the way for sustainable and energy-saving humidity control materials.