Molecular Dynamics Simulation of Polymer-Rare Earth Ions Complexes
Mostafa Khodakarami, Lana Alagha*
Department of Mining & Nuclear Engineering, Missouri S&T, Rolla, MO 65401, USA
(*corresponding author: alaghal@mst.edu)
Polymer-metal composites have formed the basis of novel materials for the last two decades especially
composites containing smart polymers that can undergo changes in response to external or internal stimuli
(stimuli-responsive polymers). Understanding metal-polymer interaction is of great importance in terms of
their potential applications in fields like laser technology, environmental protection, heavy metals recovery,
and rare earth extraction. For instance, stimuli responsive polymers can be coordinated with rare earth
metals if specific stimulus is applied and release the metal when this stimulus is removed. This can be used
to pre-concentrate REE in aqueous solution prior to solvent extraction process which can help to decrease
the amount of stripping and extraction agents compared to conventional processes. This reduction in the
consumption of reagents and solvents is desirable in terms of environmental protection point of view
especially in the field of nuclear industry when rare earth are extracted from nuclear wastes. In this work,
application of stimuli-responsive polymers (switchable polymers) for extraction of rare earth elements
(REE) is developed by using molecular dynamics (MD) simulation to probe physico-chemical necessities
for achieving stimuli-responsiveness of polymer. MD simulation runs are carried out in GROMACS
package to investigate the complexation behavior and provide an atomic level view of interactions.
Interaction mechanism between REE and polymers under different conditions including pH, temperature
and REE concentration is modeled in order to describe the desired phase transition according to outputs of
MD simulation.
KEYWORDS
Molecular dynamics, Rare earth elements, Stimuli-responsive polymers, Complexation