Abstract: Electrified liquid-liquid extraction systems including an alkyl-substituted ferrocene compound as an organic adsorbent are provided herein. Methods of recovering a metal from a leach solution are further provided.

Abstract: Redox copolymers for electrochemically-assisted electrosorption and release of an organic micropollutant from a contaminated water source are provided. Electrochemical systems including the redox copolymers immobilized to a first electrode such that the first electrode is configured to be tunable in redox activity, hydrophobicity, fluorophilicity, and/or binding affinity, and to be tunable toward a target molecule, are further provided. Methods of and systems for separating and degrading a target molecule in tandem from a fluid are further provided.

Abstract: Rare earth elements (REEs) play an essential role in our modern society, being critical resources for the growing electronic devices and renewable energy technologies. For the reversible capture and release of REEs, we designed and synthesized a redox-copolymer poly(ferrocenylpropyl methacrylamide-co-methacrylic acid) (P(FPMAm-co-MAA)) that combines an ion-exchange carboxylic acid group for REE adsorption, and an redox-active ferrocene moiety for electrochemical regeneration. By molecularly tuning the copolymer composition, efficient adsorption uptake could be achieved alongside electrochemically regenerated adsorbent reuse. The copolymer sorbent showed stoichiometric binding for yttrium (Y), cerium (Ce), neodymium (Nd), europium (Eu), gadolinium (Gd), and dysprosium (Dy) based on carboxylic acid active site.

Abstract: A system for redox-mediated electrodialysis includes: a first electrode; a second electrode positioned in opposition to the first electrode; an anion exchange membrane and a cation exchange membrane positioned between the first and second electrodes; a feed channel for flow of a treating fluid, the feed channel extending between the anion and cation exchange membranes; an additional membrane or pair of membranes between the first and second electrodes, the additional membrane or pair of membranes defining a collection channel on one or both sides of the feed channel for collecting anions and cations removed from the treating fluid, the additional membrane or pair of membranes including an anion exchange membrane and/or a cation exchange membrane; and a redox channel for flow of a redox fluid, the redox channel containing the first and second electrodes and being separated from the feed and/or collection channels by the anion and/or cation exchange membranes.

Abstract: The design of electrochemically responsive halogen donors in redox-active polymer for switchable electrosorption and release of anions. A redox-active group such as ferrocene acts as an electron-withdrawing group, facilitating the delocalization of the electrons on the halogen atom. Upon the oxidation of the ferrocene moiety, the halogen atom forms a partial-positive charge (?-hole) on the elongation of the C—I bond, resulting in strong binding with anions in cooperation with the hydrogen bonds on the cyclopentadienyl ring on the oxidized ferrocene. During reduction of ferrocene, halogen bonding is deactivated, releasing the bound anions reversibly.

Abstract: Chiral redox-polymers that have been enabled for electrochemically-controlled enantioselective interactions. Supramolecular chirality was leveraged for enhancing recognition toward target enantiomers. Chiral redox-metallopolymers were synthesized based on Ugi's amine-inspired chiral monomers, and their enantioselective recognition toward ionic enantiomers, such as tryptophan and naproxen, is demonstrated, with higher enhancement provided by a chiral redox-polymer over a single-site, chiral building block. 2D nuclear magnetic resonance spectroscopy and solid-state circular dichroism support supramolecular chirality resulting from the intramolecular interaction between the ferrocene and the alkyl group in the backbone. The chiral redox-metallopolymers can be used as a platform for electrochemically-modulated enantioselective interactions toward a range of amino acids and pharmaceutical carboxylates.

Abstract: A system for redox polymer electrodialysis includes: a first electrode; a second electrode positioned in opposition to the first electrode; a pair of size-exclusion membranes positioned between the first and second electrodes; an ion exchange membrane positioned between the pair of size-exclusion membranes, the ion exchange membrane defining a feed channel and an accumulating channel between the size-exclusion membranes; and a redox channel containing the first and second electrodes and being separated from the feed and/or accumulating channels by the pair of size-exclusion membranes.