Lanthanide Binding Tag Peptides for Selective Separation of Rare Earth Elements

Author

Luis E. Ortuno Macias, CUNY City CollegeFollow

Date of Award

2025

Document Type

Thesis

Department

Chemical Engineering

First Advisor

Charles Maldarelli

Second Advisor

Raymond Tu

Keywords

LBT, peptides, rare earth elements, separation, interfaces, self-assembly

Abstract

The rising demand for rare earth elements (REEs) necessitates more sustainable and selective separation methods. This research explores peptide-based strategies using lanthanide-binding tags (LBTs), short peptides that coordinate REEs with high affinity. Two approaches are investigated: (1) Foam-based separations, where LBT:REE complexes adsorb to the air-water interface and are collected in foam. Surface tension, x-ray reflectivity, and fluorescence techniques demonstrate selective interfacial adsorption of Tb³⁺. Cross-linking with glutaraldehyde enhances foam stability and separation efficiency. (2) Self-assembly of LBT:REE complexes into nanoscale aggregates, characterized by dynamic light scattering, electron microscopy, and anomalous small angle x-ray scattering. Circular dichroism spectroscopy reveals that metal coordination influences peptide conformation and aggregation via hydrophobic and aromatic interactions. This work integrates interfacial science, macromolecular assembly, and coordination chemistry to advance biomolecular platforms for selective and sustainable REE recovery.

Recommended Citation

Ortuno Macias, Luis E., "Lanthanide Binding Tag Peptides for Selective Separation of Rare Earth Elements" (2025). CUNY Academic Works.
https://academicworks.cuny.edu/cc_etds_theses/1278