Electro‐responsive functional materials can play a critical role in selective metal recovery and recycling due to the need for molecular differentiation between transition metals in complex mixtures. Redox‐active metallopolymers are a promising platform for electrochemical separations, offering versatile structural tuning and fast electron transfer. First, through a judicious selection of polymer structure between a main‐chain metallopolymer (polyferrocenylsilane) and a pendant‐group metallopolymer (polyvinylferrocene), charge‐transfer interactions and binding strength toward competing metal ions are tuned, which as a result, dictate selectivity. For example, almost an order of magnitude increase in separation factor between chromate and meta‐vanadate can be achieved, depending on polymer structure. Second, these metallopolymer electrodes exhibit potential‐dependent selectivity that can even flip ion preference, based solely on electrical means—indicating a control parameter that is orthogonal to structural modifications. Finally, this work presents a framework for evaluating electrochemical separations in multicomponent ion mixtures and elucidates the underlying charge‐transfer mechanisms resulting in molecular selectivity through a combination of spectroscopy and electronic structure calculations. The findings demonstrate the applicability of redox‐metallopolymers in tailored electrochemical separations for environmental remediation, value‐added metal recovery, waste recycling, and even mining processing.

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The present work examines an in-situ NMR technique for the copolymerization of methyl methacrylate (MMA) and diallyl dimethylammonium chloride (DADMAC). The copolymer poly(MMA-co-DADMAC) contains monomers of significantly different polarities, making it challenging to measure DADMAC incorporation. The conventional technique for accurate measurement of monomer reactivity ratios in copolymers is time consuming, requiring a large number of experiments, in addition to being challenging for isolation/analysis of formed copolymers from this heterogeneous polymerization. The results show that the reactivity ratios were insensitive to temperatures between 60 and 80 °C, while the reactivity ratios of MMA were found to be much higher than that of DADMAC. The results were comparable to those obtained by the conventional technique. Due to the heterogeneous nature, the measured reactivity ratios are considered as apparent reactivity ratios but important for modifying poly(methyl methacrylate) with DADMAC by copolymerization, enabling design and development of copolymers with desired composition for specific end-use applications.

Understanding of protein conformational dynamics is essential for elucidating molecular origins of protein structure-function relationship. Traditionally, reaction coordinates, i.e., some functions of protein atom positions and velocities have been used to interpret the complex dynamics of proteins obtained from experimental and computational approaches such as molecular dynamics simulations. However, it is nontrivial to identify the reaction coordinates a priori even for small proteins. Here, we evaluate the power of evolutionary couplings (ECs) to capture protein dynamics by exploring their use as reaction coordinates, which can efficiently guide the sampling of a conformational free energy landscape. We have analyzed 10 diverse proteins and shown that a few ECs are sufficient to characterize complex conformational dynamics of proteins involved in folding and conformational change processes. With the rapid strides in sequencing technology, we expect that ECs could help identify reaction coordinates a priori and enhance the sampling of the slow dynamical process associated with protein folding and conformational change.