Wireless bipolar electrochemistry for complex matrix resolution: mechanistic insight via atomistic modeling and spearmint oil purification

This work introduces a solvent-sparing platform for chemical purification that challenges conventional energy-intensive separation methods by exploiting the “wireless” nature of Bipolar Electrochemistry (BE). We present a miniaturized device based on inherently chiral oligo-modified polypyrrole (Ppy) hollow tubes that functions as an ultra-precise, electrochemically-driven pump for complex matrices. The system is actuated wirelessly via an external electric field, inducing asymmetric polarization across the conductive polymer interface and eliminating the need for direct electrical connections. We exploit the inherent chiral affinity of the solid-state polymer interface, quantified by substantial Cyclic Voltammetry (CV) potential differentials (up to 220 mV), as an electrochemical switch to control kinetic selectivity. Crucially, atomistic modeling (DFT/MD) validates this mechanism, revealing that the separation is driven by a differential Gibbs Free Energy of Adsorption (ΔΔG ads ) of 21.2 kJ/mol, which significantly suppresses the effective diffusion coefficient ( D eff ) of the favored enantiomer within the polymer matrix. When applied to the direct purification of neat spearmint oil, this wireless electro-pumping achieved high enrichment of key monoterpenoids ((-)-carvone and (-)-limonene) up to 90% relative purity, while preserving high enantiomeric excess (ee > 90%). This study provides a robust proof-of-concept for integrating computational design with wireless electrochemical actuation for sustainable downstream processing.