biostudies-literatureUnknown5(9)Miyake JProton exchange membranes (PEMs), Nafion as a representative, are one of the key materials for energy-converting devices such as fuel cells, water electrolyzers, and redox flow batteries. Recently, environmental concerns regarding perfluoro compounds (e.g., PFAS) have been issues; thus, synthesis of PEMs with mitigated environmental impact is highly demanded. In this paper, we describe that a one-pot synthesis from cellulose provides highly proton conductive cellulose-based PEMs (<b>SC-1</b>) very effectively. The <b>SC-1</b> with ion exchange capacity ranging from 1.07-1.49 mmol g^-1 was successfully prepared by controlling the feed molar ratio of the reactants. ¹H NMR spectra, titration, and elemental analysis supported the successful synthesis of <b>SC-1</b> with a high purity and well-defined structure. Consequently, our synthetic method provided <b>SC-1</b> with a high degree of substitution (1.87-2.48), which was advantageous for membrane properties. For example, the maximum H⁺ conductivity of the <b>SC-1</b> membranes exceeded 140 mS cm^-1 (in water at 60 °C) with a suppressed water uptake value (69%), which is one of the best performances among cellulose-based PEMs. The <b>SC-1</b> membranes also showed good acid resistivity in 2 M H₂SO₄ at 30 °C for 24 h.JACS Au4165-4169https://www.ebi.ac.uk/biostudies/studies/S-EPMC12458048biostudies-literatureCellulose Proton Conductor: Both Sulfonic Acid and Hydrophobic Group Functionalization Enable High Proton Conductivity.PMC12458048Miyake JfalseCellulose Proton Conductor: Both Sulfonic Acid and Hydrophobic Group Functionalization Enable High Proton Conductivity.Proton exchange membranes (PEMs), Nafion as a representative, are one of the key materials for energy-converting devices such as fuel cells, water electrolyzers, and redox flow batteries. Recently, environmental concerns regarding perfluoro compounds (e.g., PFAS) have been issues; thus, synthesis of PEMs with mitigated environmental impact is highly demanded. In this paper, we describe that a one-pot synthesis from cellulose provides highly proton conductive cellulose-based PEMs (<b>SC-1</b>) very effectively. The <b>SC-1</b> with ion exchange capacity ranging from 1.07-1.49 mmol g^-1 was successfully prepared by controlling the feed molar ratio of the reactants. ¹H NMR spectra, titration, and elemental analysis supported the successful synthesis of <b>SC-1</b> with a high purity and well-defined structure. Consequently, our synthetic method provided <b>SC-1</b> with a high degree of substitution (1.87-2.48), which was advantageous for membrane properties. For example, the maximum H⁺ conductivity of the <b>SC-1</b> membranes exceeded 140 mS cm^-1 (in water at 60 °C) with a suppressed water uptake value (69%), which is one of the best performances among cellulose-based PEMs. The <b>SC-1</b> membranes also showed good acid resistivity in 2 M H₂SO₄ at 30 °C for 24 h.2025-01-01T00:00:00Z2025 Sep2026-06-03T20:19:19.134Z2026-05-01T03:10:46.572ZS-EPMC124580484100165310.1021/jacsau.5c00547