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DOE OSTI2021

Experimental Protocols for Studying Organic Non-aqueous Redox Flow Batteries

We report that Redox flow batteries (RFBs) are promising devices for grid-scale energy storage due to the decoupling of power and energy, which can be independently scaled by the electrode area and storage tank size, respectively. To date, only aqueous RFBs, such as the vanadium RFB, have been implemented commercially. Nevertheless, the limited energy densities and high-cost materials may preclude their wider market penetration. Organic non-aqueous redox-flow batteries (O-NRFBs), which utilize redox-active organic molecules (ROMs), have been offered as an attractive alternative. Many possible advantages include the use of earth-abundant elements (C, H, N, O, S, F), wherein the ROMs can be prepared from low-cost and sustainable materials. Additionally, a large variety of electroactive moieties are accessible as building blocks, providing a synthetic platform to tune the properties of ROMs through rational design. As a consequence, the development of novel ROMs has attracted researchers with diverse backgrounds, prompting remarkable innovations in the past decade. However, consistency in experimental protocols (e.g., electrochemical methods, cycling stability, experimental conditions) has not coincided with this uptick in research, leading to sometimes ambiguous and incomparable results. This is further convoluted by the complexity innate to battery development, such as cell design, detection, and characterization of reactions and active components. The O-NRFB application imposes stringent requirements on the physical or/and chemical processes involved in electrochemical cycling. Yet such considerations are often overlooked. Further, while quantum mechanical calculations provide a convenient tool for evaluating and selecting ROM candidates, this simulation is not always performed. Thus, in this Energy Focus, we detail a means to standardize experimental protocols for studies of O-NRFBs and suggest practices to facilitate fundamental understanding and development of ROMs.

25 ENERGY STORAGE↗

DOE OSTI2021

Advanced strategies for the development of porous carbon as a Li host/current collector for lithium metal batteries

Lithium metal is considered a promising anode material for high-energy-density rechargeable batteries because of its high specific theoretical capacity (3860 mAh g -1 , low mass density (0.534 g cm -3 ), and low electrochemical redox potential (-3.04 V vs. the standard hydrogen electrode). However, the high reactivity of Li with the electrolyte leads to the formation of an unstable solid electrolyte interphase (SEI) and continuous side reactions. Also, the non-uniform lithium-ion flux and infinite volume expansion of Li metal cause the growth of Li dendrites. These pose significant safety challenges and cause rapid capacity fading of the lithium metal batteries (LiMBs). To resolve these issues, a low-cost, easily processed, lightweight, high-performance carbon-based porous matrix is considered promising to host Li metal deposition. The three-dimensional (3D) porous nano/microstructured carbon provides sufficient space for Li accommodation during Li plating, buffers the volume changes during Li plating/stripping, and lowers the effective current density contributing to dendrite-free Li deposition. Besides, the outstanding electrochemical and mechanical stability, flexibility and the high electronic conductivity enable the nano/microstructured carbon to serve as both Li host and current collector. The development of 3D carbon/Li composite by mechanical roll-press techniques not only eliminates the complex and risky procedure of making carbon/Li composite based on Li plating or molten Li infusion but also stabilizes the capacity at higher Li plating/stripping rates. Recently, there is an advancement in the lithiophilic decorations of 3D structure to introduce sufficient nucleation sites and the development of artificial SEI on top of the 3D matrix to suppress Li dendrite formation. Such 3D structural modifications create a uniform electric field, lower the Li nucleation overpotential, provide strong mechanical and chemical stability, and stabilize the interface thereby inhibiting the degradation of lithium and the electrolyte. Here we summarize the research progress on porous carbon/Li composites in terms of materials type, structure, fabrication technique, their electrochemical battery performance, and identify the critical challenges that need to be addressed for high-energy-density practical LiMBs.

25 ENERGY STORAGE↗

NASA NTRSDate not supplied

A New Era of H-O-C-S Magma Solubility Modeling: Better, Faster, Stronger

H 2 O, CO 2 , and S are the most abundant volatiles in magmatic systems and are critical to understanding magma storage, phase equilibria, and volcanic eruptions. Models that consider all three of these components, however, may not allow for critical examination and adjustment of assumptions underlying the model, or provide benchmark testing or extensible interfaces. Thus, understanding why models produce different results can be challenging. We have gathered authors of established (D-Compress) and recent (VolFe, EVo, Sulfur_X, MAGEC) H-O-C-S volatile solubility models to work together to understand how and why our models diverge. We present a series of benchmark basalt degassing scenarios revealing that often understated model assumptions such as fO 2 buffer equations, fO 2 -Fe 3+ /ΣFe relationships, and even major element normalization routines have outsized effects on model results. All models consider S 2- and S 6+ melt species but with different approaches to sulfate/sulfide capacities, partition coefficients, and species fugacities, leading to divergence in the evolution of modeled gas compositions, melt S and Fe speciation, and fO 2 , with the extent of divergence depending on melt composition. Such scenarios enable meaningful intercomparison of existing models and lay the groundwork for a user-friendly yet powerful solubility modeling framework. Given our wealth of existing solubility literature, we suggest that the field of magmatic volatiles should focus now on the creation of modern tools and the modular implementation of existing model equations or methods, and that the evaluation of code usability, transparency, and benchmarking should be codified pillars of the peer-review process. As an example of such an endeavor, we present early work coupling these sulfur solubility models with VESIcal, an extensible and rigorously tested python library containing seven existing H 2 O-CO 2 solubility models. VESIcal includes the ability to extract, edit, and even interchange assumptions underlying any model. For example, users may combine or swap separately published H 2 O, CO 2 , and S models, as well as underlying model choices, such as Equations of State and redox models.

volatiles in magmas↗

DOE OSTI2026

A Quinoidal Two‐Dimensional Metal–Organic Framework for High‐Performance Micro‐Supercapacitors and Solid‐State Lithium Batteries

Two-dimensional (2D) metal-organic frameworks (MOFs) integrating redox-active linkers enable dense charge sites and open ion pathways for microscale energy storage. We report a quinoidal dicarboxylate ligand, AQM-H2L, derived from p-azaquinodimethane, forming crystalline frameworks with Cu2+ and Zn2+ nodes. The Cu-based MOF (AQM-AQM-H2L-Cu) exhibits layered sheets (>14 Å spacing) constructed from dinuclear Cu-carboxylate units and conjugated AQM linkers, which narrow the bandgap and introduce Cu2+/Cu+ pseudocapacitance. Exfoliated nanosheets (∼5 nm) retain crystallinity and excellent processability. Integrated into graphene films, they deliver areal and volumetric capacitances of 29.6 mF cm-2 and 18.1 F cm-3, achieving 2.6 mWh cm-3 energy density at 160 mW cm-3. As ionic fillers (1 wt%) in PEO solid polymer electrolytes, the nanosheets markedly enhance LiFePO4 cell performance, affording 169.8 mAh g-1 at 0.2 C and 93% retention after 400 cycles. This work establishes quinoidal linkers as a compact and robust design motif for ionically active 2D frameworks toward high-performance miniature and solid-state energy devices.

Chen, Ziman↗

DOE OSTI2020

Electrowetting‐Mediated Transport to Produce Electrochemical Transistor Action in Nanopore Electrode Arrays

Abstract Understanding water behavior in confined volumes is important in applications ranging from water purification to healthcare devices. Especially relevant are wetting and dewetting phenomena which can be switched by external stimuli, such as light and electric fields. Here, these behaviors are exploited for electrochemical processing by voltage‐directed ion transport in nanochannels contained within nanopore arrays in which each nanopore presents three electrodes. The top and middle electrodes (TE and ME) are in direct contact with the nanopore volume, but the bottom electrode (BE) is buried beneath a 70 nm silicon nitride (SiN x ) insulating layer. Electrochemical transistor operation is realized when small, defect‐mediated channels are opened in the SiN x . These defect channels exhibit voltage‐driven wetting that mediates the mass transport of redox species to/from the BE. When BE is held at a potential maintaining the defect channels in the wetted state, setting the potential of ME at either positive or negative overpotential results in strong electrochemical rectification with rectification factors up to 440. By directing the voltage‐induced electrowetting of defect channels, these three‐electrode nanopore structures can achieve precise gating and ion/molecule separation, and, as such, may be useful for applications such as water purification and drug delivery.

Kwon, Seung‐Ryong↗

DOE OSTI2021

Role of Polysulfide Anions in Solid-Electrolyte Interphase Formation at the Lithium Metal Surface in Li–S Batteries

Delineating intricate interactions between highly reactive Li-metal electrodes and the diverse constituents of battery electrolytes has been a long-standing scientific challenge in materials design for advanced energy storage devices. Here, we isolated lithium polysulfide anions (LiS 4 - ) from an electrolyte solution based on their mass-to-charge ratio and deposited them on Li-metal electrodes under clean vacuum conditions using ion soft landing (ISL), a highly controlled interface preparation technique. The molecular level precision in the construction of these model interfaces with ISL, coupled with in situ x-ray photoelectron spectroscopy and ab initio theoretical calculations, allowed us to obtain unprecedented insight into the parasitic reactions of well-defined polysulfides on Li-metal electrodes. Our study reveals that the oxide-rich surface layer, which is amenable to direct electron exchange, drives multielectron sulfur oxidation (S o → S 6+ ) processes. Furthermore, our results have substantial implications for the rational design of future Li-S batteries with improved efficiency and durability.

25 ENERGY STORAGE↗

DOE OSTI2025

Electrochemical Characterization of Dissolved Oxides in Molten FLiNaK

Molten fluoride salts have long been the subject of investigation given their application in a variety of industrial processes. Oxides are a common exogeneous impurity within these systems, and can lead to many operational and regulatory concerns. In recent studies, the electro-oxidation of dissolved metallic oxides has been attributed to a single step oxygen evolution reaction despite voltametric evidence suggesting otherwise. Here, we first use square wave voltammetry to confirm that the oxidation of dissolved oxides in fluorides proceeds via a two-electron transfer reaction and then demonstrate that the presence of a peroxide-mediated redox reaction better explains the electrochemical data. Numerical simulations were then used to support the determination of improved diffusion coefficients to enable electroanalytical measurements of the oxide concentration across at a variety of temperatures. A linear Arrhenius relationship was observed when the experimental data was corrected for ohmic resistance effects. Concentration measurements using the corrected square wave voltammetry data demonstrated high accuracy across a large range of concentrations, while the uncorrected data showed plateauing and high errors. In total, this work serves to rectify previously misconstrued electrochemical data of oxides in molten salts and demonstrate how accurate, in situ concentration measurements can be achieved in real-world systems.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2025

Data for Stetten et al. (2025), "Biogeochemical controls on iron speciation and cycling across upland to shoreline gradients in freshwater and estuarine coastal soils (Lake Erie and Chesapeake Bay, United States)"

Coastal environments are dynamic interfaces that mediate carbon and nutrient exchanges between terrestrial landscapes and open waters, but it is unclear how biogeochemical reactions, in particular iron (Fe) redox transformations, affect the understanding and prediction of coastal ecosystem functions. This dataset includes measurements from two freshwater sites in the Western and Central basins of Lake Erie (Ohio, United States) and two estuarine sites in the Chesapeake Bay (Maryland, United States); the analytical results were reported by Stetten et al. (2025) in Science of the Total Environment. It was produced as part of the COMPASS-FME project, which seeks to advance a scalable, predictive understanding of the fundamental biogeochemical processes, ecological structure, and ecosystem dynamics that distinguish coastal terrestrial-aquatic interfaces from the purely terrestrial or aquatic systems to which they are coupled. The sites were sampled in November 2022 (CRC), December 2022 (MSM), February 2023 (GCW), and March 2023 (OWC); site codes follow those used by Pennington et al. (2025).The dataset consists of the following soil data:- Solid data (Fe concentration, etc.)- Porewater data (sulfate, sulfide, etc.)- Linear combination fitting results of X-ray absorption near edge structure (XANES) spectra; i.e., quantitative results of the oxidation state of Fe, indicated as a proportion of pure Fe(III) and Fe(II) model compounds- Linear combination fitting results of EXAFS (extended X-ray absorption fine structure) spectra, indicated as proportion of of Fe-model compounds (illite, smectite, etc.)Each data type has a single file in comma-separated value (CSV) format. No special software is required to read it.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRS2012

Chemical and Mineralogical Characterization of Acid-Sulfate Alteration of Basaltic Material on Mauna Kea Volcano, Hawaii: Jarosite and Hydrated Halloysite

Sulfates have been identified on the martian surface during robotic surface exploration and by orbital remote sensing. Measurements at Meridiani Planum (MP) by the Alpha-Particle X-ray Spectrometer (APXS) and Mossbauer (MB) instruments on the Mars Exploration Rover Opportunity document the presence of a ubiquitous sulfate-rich outcrop (20-40% SO3) that has jarosite as an anhydrous Fe3+-sulfate [1- 3]. The presence of jarosite implies a highly acidic (pH <3) formation environment [4]. Jarosite and other sulfate minerals, including kieserite, gypsum, and alunite have also been identified in several locations in orbital remote sensing data from the MEx OMEGA and MRO CRISM instruments [e.g. 5-8]. Acid sulfate weathering of basaltic materials is an obvious pathway for formation of sulfate-bearing phases on Mars [e.g. 4, 9, 10]. In order to constrain acid-sulfate pathways on Mars, we are studying the mineralogical and chemical manifestations of acid-sulfate alteration of basaltic compositions in terrestrial environments. We have previously shown that acidsulfate alteration of tephra under hydrothermal conditions on the Puu Poliahu cone (summit region of Mauna Kea volcano, Hawaii) resulted in jarosite and alunite as sulfate-bearing alteration products [11-14]. Other, more soluble, sulfates may have formed, but were leached away by rain and melting snow. Acidsulfate processes on Puu Poliahu also formed hematite spherules similar (except in size) to the hematite spherules observed at MP as an alteration product [14]. Phyllosilicates, usually smectite }minor kaolinite are also present as alteration products [13]. We discuss here an occurrence of acid-sulfate alteration on Mauna Kea Volcano (Hawaii). We report VNIR spectra (0.35-2.5 microns ASD spectrometer), Mossbauer spectra (MER-like ESPI backscatter spectrometer), powder XRD (PANalytical), and major element chemical compositions (XRF with LOI and Fe redox) for comparison to similar data acquired or to be acquired by MRO-CRISM and MEx OMEGA, MERMB, MSL-CheMin, and MER and MSL APXS, respectively.

Graff, Trevor G.↗

DOE OSTI2020

Influence of fuel ash on the recoverability of copper from the spent material of chemical looping combustion

Chemical looping combustion (CLC) is an advanced energy production technology that inherently separates the CO 2 generated. The oxygen needed for fuel conversion is supplied by the oxygen carrier. When using copper-based oxygen carriers, oxygen carrier attrition is a challenge to the process economics, unless the attrited copper that is mixed with fuel ash in the spent material can be recovered by, for instance, acid leaching. However, fuel ash may transform the attrited copper into certain complexes of low leachability (e.g., CuAl 2 O 4 ), hindering the copper recovery. In this study, the copper content in the spent material was first evaluated. The effects of ash composition and copper content on the occurrence mode of copper in spent material were predicted by thermodynamic modeling. Redox cycles of simulated spent materials based on various coal ashes were performed to reveal the characteristics of CuAl 2 O 4 /CuFe 2 O 4 formation. The CuO-Al 2 O 3 reaction was investigated under the temperatures and solid residence times experienced in CLC. The materials were analyzed by X-ray diffraction. The results suggest that the fuel ash with a high Al/Ca ratio may lower the recoverability of copper when the temperature is above 925 °C. The slow formation of CuFe 2 O 4 is not expected to affect the copper recovery.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2019

Bonding Interactions in Uranyl α-Diimine Complexes: A Spectroscopic and Electrochemical Study of the Impacts of Ligand Electronics and Extended Conjugation

Uranyl complexes of aryl-substituted α-diimine ligands gbha (UO 2 -1a-f and phen-BIAN (UO 2 -2a-f) (gbha (1) = glyoxal bis(2-hydroxyanil); phen-BIAN (2) = N,N' -bis-(iminophenol)acenaphthene; R = OMe (a), t-bu (b), H (c), Me (d), F (e), and naphthyl (f)) were designed, prepared, and characterized by X-ray diffraction, FT-IR, NMR, UV-Vis, and electrochemical methods. Furthermore these ligand frameworks contain a salen-type O-N-N-O binding pocket, but are redox-non-innocent, leading to unusual metal complex behaviors. Here, we describe three solid-state structures of uranyl complexes UO 2 -1b, UO 2 -1c, and UO 2 -1f, and observe manifestations of ligand non-innocence for the U(VI) complexes UO 2 -1b and UO 2 -1c. The impacts of accessible π-systems and ligand substitution on the axial uranium-oxo interactions can be evaluated spectroscopically via the intraligand charge-transfer (ILCT) processes that dominate the absorption spectra of these complexes and through changes to the asymmetric (ν 3 ) O=U=O stretching frequency. This, in combination with electrochemical data, reveals the effects of the inclusion of the conjugated acenaphthene backbone and the importance of ligand electronic structure on uranyl’s bonding interactions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

NASA NTRS1980

Anion permselective membrane

The efforts on the synthesis of polymer anion redox membranes were mainly concentrated in two areas, membrane development and membrane fabrication. Membrane development covered the preparation and evaluation of experimental membranes systems with improved resistance stability and/or lower permeability. Membrane fabrication covered the laboratory scale production of prime candidate membranes in quantities of up to two hundred and sizes up to 18 inches x 18 inches (46 cm x 46 cm). These small (10 in x 11 in) and medium sized membranes were mainly for assembly into multicell units. Improvements in processing procedures and techniques for preparing such membrane sets lifted yields to over 90 percent.

Hodgdon, R. B.↗

NASA NTRSDate not supplied

Improving Data Analyses for a Biological Mission to Deep Interplanetary Space

Onboard the Artemis 1 rocket, NASA plans to launch the first deep space bioscience mission past low Earth orbit (LEO) since 1972, BioSentinel, a 6-Unit (6U) biological CubeSat. BioSentinel’s goals are to assess the effect of deep space ionizing radiation (IR) on DNA and cell damage response, using Saccharomyces cerevisiae, or budding yeast, as a model organism. BioSentinel accomplishes this by measuring Optical Density (OD) in addition to metabolic activity using the redox dye alamarBlue, both of which will be read through light emitting diode (LED) lights of differing wavelengths. With the largest and most sophisticated energy-providing solar panels utilized on a biological CubeSat to date, BioSentinel will be equipped with an IR dosimeter to identify what doses of radiation the yeast is exposed to at any point in time, in addition to a transponder to send such data back to NASA Ames’ Multi Mission Operations Center (MMOC). Biology computational programs and data processing scripts are necessary to analyze this complex data once it is received, including automated subroutines to analyze duplication rate, alamarBlue reduction, and time periods when paired against numerous other variables. Overall, we have implemented several VisualBasic biocomputational programs to analyze such data in an organized and efficient manner so that conclusions can be made rapidly. Furthermore, we showcase why efficient analysis of particular parameters is important to better understand the risks that deep space IR poses to astronauts, especially when considering the upcoming Artemis missions.

Bijan Harandi↗

NASA NTRSDate not supplied

Investigating Biological Responses to Deep Space Radiation for Missions Beyond Low Earth Orbit (LEO) using Yeast

To enable long-term spaceflight missions and establish habitation on the Moon and Mars, we require a comprehensive understanding of the effects of chronic deep space radiation exposure on humans. BioSentinel is NASA’s first biological CubeSat to venture beyond Low Earth Orbit (LEO). It utilizes Saccharomyces cerevisiae (budding yeast) as a model organism to study biological responses to deep space radiation. Yeast share significant genetic homology with humans, including basic cellular metabolism and DNA repair mechanisms. In addition, unlike human cell cultures, yeast can survive the duration and constraints of a deep space mission. BioSentinel measures biological responses using an optical system and alamarBlue oxidation-reduction (redox) dye. Two strains of yeast are studied - a wild-type and a rad51 mutant strain that is deficient in DNA repair. Changes in metabolism and growth are monitored throughout the nominal 6-month mission. Preliminary tests indicate a significant change in the alamarBlue response to low-dose ionizing radiation (IR). Additionally, rad51 cells have shown an IR dose-dependent decrease in glucose uptake and accumulation of oxidized NADH (NAD+). These biomolecules are involved in reactions responsible for basic cell processes, including growth and development, signaling, and respiration. The current study expanded upon previous data by exposing yeast to deep space-relevant radiation. Glucose and NADH/NAD+ assays were conducted on yeast subjected to varying dosages of high-energy Fe-56 and simulated galactic cosmic rays (GCRs). The resulting data was analyzed using Excel and GraphPad Prism. A particular focus was to identify biomolecules resulting from aerobic respiration, which requires the presence of oxygen, or anaerobic processes. As long-term spaceflight missions draw near, it is increasingly important to characterize biological processes affected by the conditions of deep space. Studying biomolecular damage caused by deep space radiation may enable the development of engineering controls or biomedical therapeutics that mitigate health complications for future astronauts.

Kyra Keenan↗

DOE OSTI2016

An enhanced mangiferaindica for dye sensitized solar cell application

Titanium dioxide (T1O2) is preferred to Zinc oxide as mesoporous oxide layer because it raised the efficiency of DSSCs from 1% to 7%. The chemistry of the process however seem rigorous to allow the light induced electron injection from the adsorbed dye into the nanocrystallites i.e. which renders the TiO{sub 2} conductive. The DSSC fabricated consist of 2.25 cm{sup 2} active area of titanium dioxide coated on FTO glass (fluorine tin oxide) immersed in ethanol solution of natural dye extracted as an anode (electrode) and counter electrode. These two electrodes were coupled together and the space between them was filled with the Iodolyte AN-50 as solid electrolyte or redox mediator. The photo electrochemical parameters of the dye extracted (Mango fruit Peel) from the results obtained are short circuit current (Isc)= 1.22×10{sup −2}, current density (Jsc)=4.07×10{sup −2}, open circuit voltage (voc) =0.53V, fill factor (FF) of 0.16 and the overall conversion efficiency (Eff) =0.345%.

36 MATERIALS SCIENCE↗

DOE OSTI2022

Topology Optimization of 3D Flow Fields for Flow Batteries

We report as power generated from renewables becomes more readily available, the need for power-efficient energy storage devices, such as redox flow batteries, becomes critical for successful integration of renewables into the electrical grid. An important aspect of a redox flow battery is the planar flow field, which is usually composed of two-dimensional channels etched into a backing plate. As reactant-laden electrolyte flows into the flow battery, the channels in the flow field distribute the fluid throughout the reactive porous electrode. We utilize topology optimization to design flow fields with full three-dimensional geometry variation, i.e., 3D flow fields. Specifically, we focus on vanadium redox flow batteries and use the optimization algorithm to generate 3D flow fields evolved from standard interdigitated flow fields by minimizing the electrical and flow pressure power losses. To understand how these 3D designs improve performance, we analyze the polarization of the reactant concentration and exchange current within the electrode to highlight how the designed flow fields mitigate the presence of electrode dead zones. While interdigitated flow fields can be heuristically engineered to yield high performance by tuning channel and land dimensions, such a process can be laborious; this work provides a framework for automating that design process.

25 ENERGY STORAGE↗

DOE OSTI2019

Round Robin Test on Enthalpies of Redox Materials for Thermochemical Heat Storage: Perovskites

Among the potential materials proposed as suitable for thermochemical heat storage, ABO3 perovskites merit significant attention for high temperature applications in concentrating solar power plants. The specific enthalpy of the reaction is a key parameter to establish the storage capacity of the system, and accordingly determines the potential impact on decreasing related costs associated with the volume of the system. Discrepancies in the referenced enthalpies may arise from different sources like the experimental sets-ups for measuring thermodynamic properties; protocols applied or the origin of the samples. This work presents a round robin test conducted by seven institutions in order to establish a standard methodology for the measurement of enthalpies of relevant thermochemical processes at high temperature. The initiative was organized within the Working Group on Thermal Storage (Activity on 'Materials for Thermal Storage') in SolarPACES Task III.

14 SOLAR ENERGY↗

DOE OSTI2025

Impacts of Disulfide‐Containing Monomers in Alternating Diene Metathesis Polymerization

ABSTRACT Among the classes of synthetic polymers, disulfide‐containing structures offer unique opportunities due to their accessibility to redox chemistry that allows for degradation or reversible disulfide formation and exchange under mild conditions. Here, we examine the role of disulfides in olefin metathesis polymerization, specifically alternating diene metathesis (ALTMET) polymerization, for synthesizing unsaturated polyolefins with embedded disulfides. Our synthetic strategy hinged on the use of α,ω‐diacrylate monomers, including those connected by a disulfide unit, via copolymerization by the ALTMET mechanism to yield copolymers containing a range of disulfide content. In addition, the potential impacts of sulfur‐ruthenium interactions on the ALTMET process were investigated spectroscopically, while the degradation of the resultant polymers was affected by mild reducing agents. Overall, this study contributes to the development of degradable synthetic polymers using olefin metathesis methods, with an increased understanding of the potential for further use of disulfide groups in such metathesis reactions.

Lee, Kyoungwon↗