Mechanically Flexible and Weavable Hybrid Aerogel Fibers with Ultrahigh Metal–Organic Framework Loadings for Versatile Applications

Flexible and weavable metal–organic framework (MOF)-based hybrid fibers can enable many potential applications, particularly for wearable functional devices. However, the fabrication of composite textiles with high MOF loadings, a large specific surface area, and outstanding mechanical flexibility is still very challenging. Herein, we demonstrate the preparation of mechanically strong MOF@ANF (aramid nanofiber) hybrid aerogel fibers with gradient distribution of MOF crystals along the radial direction through in situ growth of MOFs on the skeletons of three-dimensional (3D)-printed aramid nanofiber (ANF) aerogel fibers. The deprotonation of poly( p -phenylene terephthalamide) networks increases the local concentration of cobalt ions and enables the in situ growth of MOF crystals inside the ANF filaments, the mechanism of which was revealed by computational simulations. As a result, an ultrahigh ZIF-67 loading of 63.4 wt % and a large specific surface area of 756.6 m 2 g –1 were achieved by the hybrid ZIF-67@ANF aerogel fibers, the highest specific surface area among macroscopic and weavable MOF-based composite fibers ever reported. These aerogel textiles show excellent mechanical flexibility and exhibit fast adsorption kinetics, high adsorption capacity, and recycling stability for addressing various hazardous pollutants, including formaldehyde vapor, heavy metal ions, and organic dyes. This work takes a further step toward wearable-MOF-based textile development for broad applications in wearable devices.