Shapeable Fibrous Aerogels of Metal–Organic-Frameworks Templated with Nanocellulose for Rapid and Large-Capacity Adsorption

Abstract

Conventional metal-organic framework (MOF) powders have periodic micro/mesoporous crystalline architectures tuned by their three-dimensional coordination of metal nodes and organic linkers. To add practical macroscopic shapeability and extrinsic hierarchical porosity, fibrous MOF aerogels were produced by synthesizing MOF crystals on the template of TEMPO-cellulose nanofibrils. Cellulose nanofibrils not only offered extrinsic porosities and mechanical flexibility for the resultant MOF aerogels, but also shifted the balance of nucleation and growth for synthesizing smaller MOF crystals, and further decreased their aggregation possibilities. Thanks to their excellent shapeability, hierarchical porosity up to 99%, and low density below 0.1 g/cm, these MOF aerogels could make the most of their pores and accessible surface areas for higher adsorption capacity and rapid adsorption kinetics of different molecules, in sharp contrast to conventional MOF powders. Thus, this scalable and low-cost production pathway is able to convert MOF powders into a shapeable and flexible form and thereby extend their applications in more broad fields, for example, adapting a conventional filtration setup.

Cross‐Linked Nanocellulosic Materials and Their Applications

“…In these homogeneous hydrogels, physical entanglement of CNFs provided strong interactions between polymer chains and metal ions. Moreover, metal ions were nucleated and grew gradually on the CNFs fiber network . The presence of these metal–carboxylate bonds can be confirmed by FTIR .…”

“…Moreover,m etal ions were nucleated and grew gradually on the CNFs fiber network. [42] The presence of these metal-carboxylate bonds can be confirmed by FTIR. [55] The chemicals hift between as trong asymmetric ÀCOOÀ stretching vibration and aw eaker symmetric ÀCOOÀ stretching vibration is the most useful characteristic band by whicht oo bserve metal-carboxylate interactions.…”

Versatile Aerogels for Sensors

“…Theoretically, as long as each compound can gelatinize itself, the hybrid aerogels consist of these compounds can be prepared. Therefore, the hybrid aerogels have extended rapidly and almost cover all kinds of aerogels . Nowadays, the preparation of hybrid aerogels has been proved to be an efficient and promising way to overcome the drawbacks of single‐compound aerogels.…”

A Spiderweb‐Like Metal–Organic Framework Multifunctional Foam

“…This aggregation problem can be reduced through in situ MOF growth, but controlling the nucleation process remains challenging, as the initially grown MOF layer on the template surface prohibits the inward diffusion of precursors, preventing nucleation and growth. Moreover, current in situ MOF growth methods are often directly connected to the fabrication of the support, which limits the ability to independently tune the material properties of each component. Another challenge created by the limited tunability of these synthetic approaches is the difficulty in introducing additional functional components to the framework material.…”