{
  "abstract": "Chemical degradation reshapes the hydrated ion-transport channels of anion exchange membranes (AEMs), but conventional aging measurements do not reveal how their nanostructure evolves toward functional failure. Here we resolve this structural evolution using high-resolution kinetic Monte Carlo (kMC) simulations. The simulations are calibrated to reproduce the experimental ion exchange capacity (IEC) and water uptake (WU) over a month degradation of a PPO-TEA membrane. The ionomer-peak position remains essentially unchanged even after 70% cation loss, while the water channels narrow from approximately 0.8 to 0.6 nm and progressively fragment. The hydrated network loses percolation at a critical hydrophilic volume fraction 𝜙!≈ 0.26, close to the threshold (𝜙!≈ 0.25) inferred from experimental conductivity using a percolation power law. Two complementary descriptions, a percolation law and a connected-carrier model, reproduce the normalized conductivity decay without using conductivity to calibrate the degradation kinetics. These results link conductivity failure to the loss of connected transport pathways within a membrane that retains its characteristic phase-separation length scale. The structural predictions are similar for two kinetic models with different dependencies on local hydration. Thus, a persistent ionomer-peak position can conceal substantial deterioration of the ion-transport network. Resolving channel connectivity along the aging trajectory provides a structural measure of membrane durability that complements conventional characterization of phase separation.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemistry",
    "University of Utah",
    "Facultad de Ciencias Exactas y Naturales",
    "Universidad de Buenos Aires",
    "Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, California, 94550"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Shakkira Erimban"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Esteban D. Gadea"
    },
    {
      "affs": [
        0,
        1,
        2,
        3
      ],
      "name": "Ignacio J. Bombau"
    },
    {
      "affs": [
        4
      ],
      "name": "John J. Karnes"
    },
    {
      "affs": [
        4
      ],
      "name": "Johanna J. Schwartz"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Valeria Molinero",
      "orcid": "0000-0002-8577-4675"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9x563at9wpjjz.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010223/v1",
  "fulltext_url": null,
  "id": "9x563at9wpjjz",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010223/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2208|Fuel Cells and Related Materials"
    ]
  ],
  "openalex": "W7221521450",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010223/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-11",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/9x563at9wpjjz.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "10.26434/chemrxiv.15010223",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010223/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "source:chemrxiv",
      "subfield": "general"
    }
  ],
  "title": "Resolving Month-Long Nanostructural Evolution in Degrading Anion Exchange Membranes",
  "title_text": "Resolving Month-Long Nanostructural Evolution in Degrading Anion Exchange Membranes",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/9x563at9wpjjz",
  "venue": "ChemRxiv",
  "versions": []
}