Mussel-Inspired Nanocellulose Coating for Selective Neodymium Recovery

Abstract

Neodymium (Nd) is one of the most in-demand rare earth elements (REEs) for developing the next generation of magnetic medical devices and clean energy. Eco-friendly and sustainable nanotechnology for REE recovery may be highly suitable to address the limited global supply while minimizing the environmental footprints of current practice, such as solvent extraction. Here, we present a novel one-step mussel-inspired nanocellulose coating (MINC) using bifunctional hairy cellulose nanocrystals (BHCNC), bearing dialdehyde and dicarboxylate groups. The dialdehyde groups enable dopamine-mediated orthogonal conjugation of BHCNC to substrates, such as microparticles, while the high content of dicarboxylate groups yields high-capacity and selective Nd removal against ferric, calcium, and sodium ions. To the best of our knowledge, the MINC-treated substrate provides the most rapid selective removal and recovery of Nd ions even at low Nd concentrations with a capacity that is among the highest reported values. We envision that the MINC will provide new opportunities in developing next-generation bio-based materials and interfaces for the sustainable recovery of REEs and other precious elements.

Chemical structure–property relationships in nanocelluloses

“…67 Crosslinking bifunctional HCNC with dopamine that has been coated on silica microparticles generates a highly functional bio-based adsorbent for selective and low-concentration rare earth element recovery. 191…”

“…The resulting composite hydrogel between bifunctional HCNC and chitosan may be freeze‐dried to yield a green aerogel with excellent reusability and high adsorption capacity for organic dyes, such as methylene blue 67 . Crosslinking bifunctional HCNC with dopamine that has been coated on silica microparticles generates a highly functional bio‐based adsorbent for selective and low‐concentration rare earth element recovery 191 …”

Modeling separation of lanthanides via heterogeneous ligand binding

“…Separating the chemically similar Ln 3+ from each other is a technologically relevant and chemically challenging problem. 3–7 Much experimental 3,5–13 and theoretical work 14–21 has focused on this separation issue using organic ligands, sometimes in organic solvents. In this work, we investigate the use of simple ligands dissolved in water, or tethered to silica and metal–organic framework interior surfaces in aqueous media, to illustrate fundamental principles that lead to differential Ln 3+ binding free energies relevant to separation.…”