Microstructure-property relationships in composites of 8YSZ ceramics and in situ graphitized nanocellulose
Ceramic matrix composites (CMC) of 8 mol.% yttria-stabilized zirconia (8YSZ) mixed with natural fiber nano cellulose (0.75, 1, 2 wt%) were prepared by spark plasma sintering (SPS). Nanocellulose markedly improved the densification of the 8YSZ ceramic matrix and induced significant grain size refinem...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/93767 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/93767 |
| Access Level: | acceso abierto |
| Palabra clave: | 538.9 YSZ Nanocellulose Ceramic matrix composite Graphitization Sintering Conductivity Física del estado sólido 2211 Física del Estado Sólido |
| Sumario: | Ceramic matrix composites (CMC) of 8 mol.% yttria-stabilized zirconia (8YSZ) mixed with natural fiber nano cellulose (0.75, 1, 2 wt%) were prepared by spark plasma sintering (SPS). Nanocellulose markedly improved the densification of the 8YSZ ceramic matrix and induced significant grain size refinement. It was demonstrated that in situ graphitization of nanocellulose during the SPS processing resulted in 6 nm thin turbostratic graphite layers homogeneously covering the 8YSZ ceramic grains. The dielectric properties were analyzed by electrical impedance spectroscopy suggesting a low percolation threshold near or below asymptotic to 1.6 vol% graphite, above which mixed ionic-electronic conduction dominates. The CMCs are stable under reducing conditions (5%H-2/Ar atmosphere) at least until 800 ? with a high conductivity of sigma(dc) = 0.17 S center dot cm(-1) even at 900 ? (8YSZ-2%CNF). These features make the 8YSZ-nanocellulose CMCs promising candidates for application in medium-to high temperature electrochemical devices. |
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