Shape Memory and Underwater Superelastic MOF@Cellulose Aerogels for Rapid and Large-capacity Adsorption of Metal Ions

Abstract Cellulose aerogels (CA) have been used in widespread areas, such as absorbents, thermal insulation material and medical material. Herein, a robust strategy to fabricate cellulose aerogels by combining cellulose nanofibers with PVA “glue”. The CA not only had a robust chemical-bond cross-link network, but also had a strong H-bond, which enhanced underwater mechanical properties. Moreover, the compressible CA provided a large number of nucleation sites for the growth of Metal-organic frame (MOF) nanoparticles (ZIF-67 and ZIF-8) through interface self-assemble. The obtained aerogels with a low density of 9.8-11.2 mg cm -3 and highly porous of 99.4-99.5% possessed excellent mechanical properties both in air and underwater. The adsorption capacities of the MOF@CA for Pb 2+ and Cu 2+ are up to 105.21 mg g -1 and 54.78 mg g -1 , respectively. The novel MOF@CA adsorbents with excellent mechanical properties display application prospects in the removal of heavy metals from wastewater.