Chen Chen, Baicheng Mei, Jingyi Zhou, Kenneth S. Schweizer, Christopher M. Evans, Paul V. Braun
{"title":"Coupling of Ethylene-Oxide-Based Polymeric Network Structure and Counterion Chemistry to Ionic Conductivity and Ion Selectivity","authors":"Chen Chen, Baicheng Mei, Jingyi Zhou, Kenneth S. Schweizer, Christopher M. Evans, Paul V. Braun","doi":"10.1021/acs.macromol.4c00539","DOIUrl":null,"url":null,"abstract":"Polymer networks are important constituents of ion separation membranes and battery electrolytes. In such systems, understanding the coupling of the network structure to ion transport is important to guide network design. However, a comprehensive understanding of how polymer network variations affect segmental relaxation and ion transport is still lacking. A series of single-anion-conducting polymer networks was synthesized with a controlled crosslinking density, ethylene oxide (EO) side chain length, tethered cationic monomer concentration, and mobile counteranion size. From dielectric spectroscopy, segmental relaxation times were obtained and found to vary by orders of magnitude across the investigated crosslinking densities and side chain lengths. Ionic conductivity is found to be coupled with segmental relaxation, which slowed with an increase in the number of crosslinks, whereas Young’s moduli of the networks are found to be most coupled with the crosslinking density. Longer side chains provide faster segmental relaxation but do not impede the mechanical strength generated by crosslinks, showing an approach toward designing networks with both high moduli and ionic conductivities. Using a similar network with added lithium salts, Li<sup>+</sup> transport selectivity is enhanced by weak interactions between Li<sup>+</sup> and large anions, as well as higher crosslinking densities.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.1000,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Macromolecules","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1021/acs.macromol.4c00539","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
Polymer networks are important constituents of ion separation membranes and battery electrolytes. In such systems, understanding the coupling of the network structure to ion transport is important to guide network design. However, a comprehensive understanding of how polymer network variations affect segmental relaxation and ion transport is still lacking. A series of single-anion-conducting polymer networks was synthesized with a controlled crosslinking density, ethylene oxide (EO) side chain length, tethered cationic monomer concentration, and mobile counteranion size. From dielectric spectroscopy, segmental relaxation times were obtained and found to vary by orders of magnitude across the investigated crosslinking densities and side chain lengths. Ionic conductivity is found to be coupled with segmental relaxation, which slowed with an increase in the number of crosslinks, whereas Young’s moduli of the networks are found to be most coupled with the crosslinking density. Longer side chains provide faster segmental relaxation but do not impede the mechanical strength generated by crosslinks, showing an approach toward designing networks with both high moduli and ionic conductivities. Using a similar network with added lithium salts, Li+ transport selectivity is enhanced by weak interactions between Li+ and large anions, as well as higher crosslinking densities.
期刊介绍:
Macromolecules publishes original, fundamental, and impactful research on all aspects of polymer science. Topics of interest include synthesis (e.g., controlled polymerizations, polymerization catalysis, post polymerization modification, new monomer structures and polymer architectures, and polymerization mechanisms/kinetics analysis); phase behavior, thermodynamics, dynamic, and ordering/disordering phenomena (e.g., self-assembly, gelation, crystallization, solution/melt/solid-state characteristics); structure and properties (e.g., mechanical and rheological properties, surface/interfacial characteristics, electronic and transport properties); new state of the art characterization (e.g., spectroscopy, scattering, microscopy, rheology), simulation (e.g., Monte Carlo, molecular dynamics, multi-scale/coarse-grained modeling), and theoretical methods. Renewable/sustainable polymers, polymer networks, responsive polymers, electro-, magneto- and opto-active macromolecules, inorganic polymers, charge-transporting polymers (ion-containing, semiconducting, and conducting), nanostructured polymers, and polymer composites are also of interest. Typical papers published in Macromolecules showcase important and innovative concepts, experimental methods/observations, and theoretical/computational approaches that demonstrate a fundamental advance in the understanding of polymers.