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K(2)O-Metakaolin-Based Geopolymer Foams: Production, Porosity Characterization and Permeability Test

In this paper, four near-net shaped foams were produced via direct foaming, starting from a benchmark metakaolin-based geopolymer formulation. Hydrogen peroxide and metallic silicon were used in different amounts as blowing agents to change the porosity from meso- to ultra-macro-porosity. Foams were...

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Autores principales: Papa, Elettra, Landi, Elena, Miccio, Francesco, Medri, Valentina
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8839599/
https://www.ncbi.nlm.nih.gov/pubmed/35160953
http://dx.doi.org/10.3390/ma15031008
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author Papa, Elettra
Landi, Elena
Miccio, Francesco
Medri, Valentina
author_facet Papa, Elettra
Landi, Elena
Miccio, Francesco
Medri, Valentina
author_sort Papa, Elettra
collection PubMed
description In this paper, four near-net shaped foams were produced via direct foaming, starting from a benchmark metakaolin-based geopolymer formulation. Hydrogen peroxide and metallic silicon were used in different amounts as blowing agents to change the porosity from meso- to ultra-macro-porosity. Foams were characterized by bulk densities ranging from 0.34 to 0.66 g cm(−3), total porosity from 70% to 84%, accessible porosity from 41% to 52% and specific surface area from 47 to 94 m(2) g(−1). Gas permeability tests were performed, showing a correlation between the pore features and the processing methods applied. The permeability coefficients k(1) (Darcian) and k(2) (non-Darcian), calculated applying Forchheimer’s equation, were higher by a few orders of magnitude for the foams made using H(2)O(2) than those made with metallic silicon, highlighting the differing flow resistance according to the interconnected porosity. The gas permeability data indicated that the different geopolymer foams, obtained via direct foaming, performed similarly to other porous materials such as granular beds, fibrous filters and gel-cast foams, indicating the possibility of their use in a broad spectrum of applications.
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spelling pubmed-88395992022-02-13 K(2)O-Metakaolin-Based Geopolymer Foams: Production, Porosity Characterization and Permeability Test Papa, Elettra Landi, Elena Miccio, Francesco Medri, Valentina Materials (Basel) Article In this paper, four near-net shaped foams were produced via direct foaming, starting from a benchmark metakaolin-based geopolymer formulation. Hydrogen peroxide and metallic silicon were used in different amounts as blowing agents to change the porosity from meso- to ultra-macro-porosity. Foams were characterized by bulk densities ranging from 0.34 to 0.66 g cm(−3), total porosity from 70% to 84%, accessible porosity from 41% to 52% and specific surface area from 47 to 94 m(2) g(−1). Gas permeability tests were performed, showing a correlation between the pore features and the processing methods applied. The permeability coefficients k(1) (Darcian) and k(2) (non-Darcian), calculated applying Forchheimer’s equation, were higher by a few orders of magnitude for the foams made using H(2)O(2) than those made with metallic silicon, highlighting the differing flow resistance according to the interconnected porosity. The gas permeability data indicated that the different geopolymer foams, obtained via direct foaming, performed similarly to other porous materials such as granular beds, fibrous filters and gel-cast foams, indicating the possibility of their use in a broad spectrum of applications. MDPI 2022-01-27 /pmc/articles/PMC8839599/ /pubmed/35160953 http://dx.doi.org/10.3390/ma15031008 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Papa, Elettra
Landi, Elena
Miccio, Francesco
Medri, Valentina
K(2)O-Metakaolin-Based Geopolymer Foams: Production, Porosity Characterization and Permeability Test
title K(2)O-Metakaolin-Based Geopolymer Foams: Production, Porosity Characterization and Permeability Test
title_full K(2)O-Metakaolin-Based Geopolymer Foams: Production, Porosity Characterization and Permeability Test
title_fullStr K(2)O-Metakaolin-Based Geopolymer Foams: Production, Porosity Characterization and Permeability Test
title_full_unstemmed K(2)O-Metakaolin-Based Geopolymer Foams: Production, Porosity Characterization and Permeability Test
title_short K(2)O-Metakaolin-Based Geopolymer Foams: Production, Porosity Characterization and Permeability Test
title_sort k(2)o-metakaolin-based geopolymer foams: production, porosity characterization and permeability test
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8839599/
https://www.ncbi.nlm.nih.gov/pubmed/35160953
http://dx.doi.org/10.3390/ma15031008
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