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 nanocellulose (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 refineme...

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Detalles Bibliográficos
Autores: Hudelja, Polona, Schmidt, Rainer, Amorín, Harvey, Drev, Sandra, Iveković, Aljaž, Abram, Anže, Kocjan, Andraž, Wicklein, Bernd
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/375871
Acceso en línea:http://hdl.handle.net/10261/375871
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129950899&doi=10.1016%2fj.jeurceramsoc.2022.04.041&partnerID=40&md5=72254360397262f78e8e8bb63fdc4f67
Access Level:acceso abierto
Palabra clave:Ceramic matrix composite
Conductivity
Graphitization
Nanocellulose
Sintering
YSZ
Descripción
Sumario:Ceramic matrix composites (CMC) of 8 mol.% yttria-stabilized zirconia (8YSZ) mixed with natural fiber nanocellulose (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 ≈ 1.6 vol% graphite, above which mixed ionic-electronic conduction dominates. The CMCs are stable under reducing conditions (5%H2/Ar atmosphere) at least until 800 °C with a high conductivity of σdc = 0.17 S∙cm−1 even at 900 °C (8YSZ-2%CNF). These features make the 8YSZ-nanocellulose CMCs promising candidates for application in medium- to high-temperature electrochemical devices. © 2022