Modernist enamels: Composition, microstructure and stability

Coloured enamels from the materials used in Modernist workshops from Barcelona were produced and compared to those found in the buildings to explore the reason for the reduced stability of the blue and green enamels. They were made of a lead-zinc borosilicate glass with a low softening point, reason...

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Detalles Bibliográficos
Autores: Beltran González, Martí|||0000-0002-4186-8768, Schibille, Nadine, Brock, Fiona, Gratuze, Bernard, Vallcorba, Oriol, Pradell Cara, Trinitat|||0000-0002-8720-5492
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/340650
Acceso en línea:https://hdl.handle.net/2117/340650
https://dx.doi.org/10.1016/j.jeurceramsoc.2019.11.038
Access Level:acceso abierto
Palabra clave:Lead zinc
Borosilicate glass
Colourants
Pigments
Microstructure
Atmospheric corrosion
Esmalts vidrats
Àrees temàtiques de la UPC::Física::Física de l'estat sòlid
Descripción
Sumario:Coloured enamels from the materials used in Modernist workshops from Barcelona were produced and compared to those found in the buildings to explore the reason for the reduced stability of the blue and green enamels. They were made of a lead-zinc borosilicate glass with a low softening point, reasonable stability to corrosion and matching thermal expansion coefficient with the blown base glass, mixed with colourants and pigment particles. The historical enamels show a lead, boron and zinc depleted silica rich amorphous glass, with precipitated lead and calcium sulphates or carbonates, characteristic of extensive atmospheric corrosion. The blue and green enamels show a heterogeneous layered microstructure more prone to degradation which is augmented by a greater heating and thermal stress affectation produced by the enhanced Infrared absorbance of blue tetrahedral cobalt colour centres and copper ions dissolved in the glass and, in particular, of the cobalt spinel particles.