Enhanced Conductivity of Chitosan Composite Membranes With Fractionated Kraft and Organosolv Lignin
[EN] Different bio-based chitosan composites containing kraft or organosolv lignin were subjected to successive solvent extractions (ethyl acetate followed by ethanol) and then modified by immersion in a sulfuric acid solution to obtain membranes with suitable conductive properties. The materials we...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:riunet.upv.es:10251/220215 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/220215 |
| Access Level: | acceso abierto |
| Palabra clave: | Chitosan composites membranes Organosolv lignin Fourier-transform infrared (FTIR) |
| Sumario: | [EN] Different bio-based chitosan composites containing kraft or organosolv lignin were subjected to successive solvent extractions (ethyl acetate followed by ethanol) and then modified by immersion in a sulfuric acid solution to obtain membranes with suitable conductive properties. The materials were characterized by Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), oxidative-stability testing, water-uptake measurements, electron and proton conductivity, and H₂/O₂ fuel-cell performance, enabling correlations between composite structure and properties. Sulfuric-acid treatment introduced sulfate groups that promote ionic interactions between polymer chains, improving resistance to radical oxidative degradation. The dry modified biocomposites exhibited very low electronic conductivity (10⁻¹⁴–10⁻¹⁰ S·cm⁻¹) over the −10 to 60 °C range, indicating potential as electrical insulators. Acid modification also disrupted crystallinity and increased hydrophilicity, leading to higher water uptake. Consequently, proton transport was enhanced, resulting in increased proton conductivity and higher power output in an H₂/O₂ fuel cell. Composites containing organosolv lignin fractions showed stronger affinity for sulfate groups and, accordingly, higher oxidative stability, greater water uptake, and improved proton conductivity compared with kraft-lignin-based composites. |
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