Engineering Hygroscopic MOF-Based Silk Via Bioinspired Interfacial Assembly for Fast Moisture Manipulation

Abstract

Metal-organic frameworks (MOFs) have emerged as exceptional moisture sorbents in low humidity conditions. However, their typical powdered form often results in agglomeration, impeding water diffusion kinetics and practical handling. To enhance the accessibility and diversify the integration of MOFs, a universal and scalable bionic interfacial assembly method is introduced for fabricating MOF-based silk. The resulting silk, enriched with a high content of MOF-303, demonstrates a significant water adsorption capacity of 315.1 mg g⁻¹ at 25% relative humidity, exhibiting a three fold faster water absorption compared with that of stacked MOFs powder on a gram-scale. Furthermore, it achieves efficient water release, with a rate of 8.1 mg g⁻¹ min⁻¹ under sunlight after surface photothermal modification. Through one-step drawing assembly, electrothermal wires can be incorporated into MOF-based silk and demonstrate fast and reversible moisture adsorption/desorption for indoor humidity control. It is envisioned that this assembling method and integrated functional silk will yield valuable insights into the rational engineering of MOFs toward practical applications in moisture management, molecule absorption, etc.