Rare-Earth Element Adsorption to Membranes Functionalized with Lanmodulin-Derived Peptides.

Area of Science:

• Materials Science
• Chemical Engineering
• Biotechnology

Background:

• Rare-earth elements (REEs) are critical for modern technologies, necessitating efficient separation methods.
• Biosorbents utilizing peptide-metal affinity offer a promising avenue for selective REE recovery.
• Enhancing binding capacity while preserving selectivity remains a key challenge for biosorbent applications.

Purpose of the Study:

• To develop and characterize a peptide-functionalized membrane adsorber for REE separation.
• To investigate the impact of hydrophilic comonomers on membrane properties and REE binding.
• To evaluate the trade-offs between binding capacity and selectivity in the developed system.

Main Methods:

• Electrospun membranes were functionalized via copolymerization of hydrophilic (2-hydroxyethyl methacrylate) and hydrophobic (allyl methacrylate) monomers.
• Peptide loading, REE affinity, and binding capacity for Lanthanum (La) and Neodymium (Nd) were measured.
• Membrane hydrophilicity, morphology, and adsorption isotherms were analyzed.

Main Results:

• Copolymerization with a hydrophilic monomer improved peptide accessibility and REE binding capacity in aqueous solutions.
• The addition of 2-hydroxyethyl methacrylate enhanced REE binding levels.
• Selectivity for Neodymium over Lanthanum (Nd/La) decreased from 2.3 to 1.1 with the hydrophilic comonomer.

Conclusions:

• Hydrophilic comonomers in peptide-functionalized membranes can increase REE binding capacity.
• Optimizing the balance between hydrophilicity and selectivity is crucial for practical REE separation using biosorbents.
• Peptide-functionalized membranes show potential for REE recovery, with further optimization needed for enhanced selectivity.