Metakaolin-red mud/carbon nanotubes geopolymer nanocomposite: mechanical properties and structural studies

In this research, the mechanical properties and structural studies of the geopolymer nanocomposite of metakaolin-red mud/carbon nanotubes were investigated. The geopolymer was designed by using metakaolin and red mud as aluminosilicate sources. Red mud replaced between 10 to 30% of the metakaolin. T...

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Main Authors: Hamidreza Ahmadi, Gholamreza Khalaj, Abolhassan Najafi, Saloumeh Mesgari Abbasi, Masumeh Safari
Format: Article
Language:English
Published: IOP Publishing 2022-01-01
Series:Materials Research Express
Subjects:
Online Access:https://doi.org/10.1088/2053-1591/ac54d6
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author Hamidreza Ahmadi
Gholamreza Khalaj
Abolhassan Najafi
Saloumeh Mesgari Abbasi
Masumeh Safari
author_facet Hamidreza Ahmadi
Gholamreza Khalaj
Abolhassan Najafi
Saloumeh Mesgari Abbasi
Masumeh Safari
author_sort Hamidreza Ahmadi
collection DOAJ
description In this research, the mechanical properties and structural studies of the geopolymer nanocomposite of metakaolin-red mud/carbon nanotubes were investigated. The geopolymer was designed by using metakaolin and red mud as aluminosilicate sources. Red mud replaced between 10 to 30% of the metakaolin. The mass ratio of the solid material and activator liquid was optimized in 1.5:1. Afterward, 1, 2, and 3 wt% multi-wall carbon nanotubes (MWCNTs) were dispersed in a polycarboxylate-based superplasticizer and were added to the geopolymer, which was mixed homogeneously. Geopolymer nanocomposites were characterized by XRD, FTIR, SEM, compressive and flexural strength measurements. The results indicated that the compressive and flexural strengths of the samples increased with curing time. The addition of red mud decreased the compressive and flexural strength of the geopolymer samples due to less reactivity and presence of a non-reactive impurity in red mud. By adding 2% MWCNTs, the compressive and flexural strengths increased to 37.05% and 36.06%, respectively, owing to the crack-bridging mechanism and filling of the cavities and porosity. FTIR spectra demonstrated the growth of the asymmetric stretching vibrations of T–O–Si (T: Si or Al) at approximately 995.85–1083.55 cm ^−1 , confirming the realization of the geopolymerization process in the structure.
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spelling doaj.art-1012d222bb7b40458f6211e2fae7726b2023-08-09T16:02:37ZengIOP PublishingMaterials Research Express2053-15912022-01-019202501110.1088/2053-1591/ac54d6Metakaolin-red mud/carbon nanotubes geopolymer nanocomposite: mechanical properties and structural studiesHamidreza Ahmadi0Gholamreza Khalaj1https://orcid.org/0000-0001-8510-4981Abolhassan Najafi2https://orcid.org/0000-0001-7396-6680Saloumeh Mesgari Abbasi3Masumeh Safari4Department of Materials Engineering, College of Technology and Engineering, Saveh Branch, Islamic Azad University , Saveh, IranDepartment of Materials Engineering, College of Technology and Engineering, Saveh Branch, Islamic Azad University , Saveh, IranDepartment of Materials Engineering, College of Technology and Engineering, Saveh Branch, Islamic Azad University , Saveh, IranDepartment of Materials Engineering, College of Technology and Engineering, Saveh Branch, Islamic Azad University , Saveh, IranDepartment of Materials Engineering, College of Technology and Engineering, Saveh Branch, Islamic Azad University , Saveh, IranIn this research, the mechanical properties and structural studies of the geopolymer nanocomposite of metakaolin-red mud/carbon nanotubes were investigated. The geopolymer was designed by using metakaolin and red mud as aluminosilicate sources. Red mud replaced between 10 to 30% of the metakaolin. The mass ratio of the solid material and activator liquid was optimized in 1.5:1. Afterward, 1, 2, and 3 wt% multi-wall carbon nanotubes (MWCNTs) were dispersed in a polycarboxylate-based superplasticizer and were added to the geopolymer, which was mixed homogeneously. Geopolymer nanocomposites were characterized by XRD, FTIR, SEM, compressive and flexural strength measurements. The results indicated that the compressive and flexural strengths of the samples increased with curing time. The addition of red mud decreased the compressive and flexural strength of the geopolymer samples due to less reactivity and presence of a non-reactive impurity in red mud. By adding 2% MWCNTs, the compressive and flexural strengths increased to 37.05% and 36.06%, respectively, owing to the crack-bridging mechanism and filling of the cavities and porosity. FTIR spectra demonstrated the growth of the asymmetric stretching vibrations of T–O–Si (T: Si or Al) at approximately 995.85–1083.55 cm ^−1 , confirming the realization of the geopolymerization process in the structure.https://doi.org/10.1088/2053-1591/ac54d6geopolymermetakaolinred mudMWCNTnanocompositemechanical strength
spellingShingle Hamidreza Ahmadi
Gholamreza Khalaj
Abolhassan Najafi
Saloumeh Mesgari Abbasi
Masumeh Safari
Metakaolin-red mud/carbon nanotubes geopolymer nanocomposite: mechanical properties and structural studies
Materials Research Express
geopolymer
metakaolin
red mud
MWCNT
nanocomposite
mechanical strength
title Metakaolin-red mud/carbon nanotubes geopolymer nanocomposite: mechanical properties and structural studies
title_full Metakaolin-red mud/carbon nanotubes geopolymer nanocomposite: mechanical properties and structural studies
title_fullStr Metakaolin-red mud/carbon nanotubes geopolymer nanocomposite: mechanical properties and structural studies
title_full_unstemmed Metakaolin-red mud/carbon nanotubes geopolymer nanocomposite: mechanical properties and structural studies
title_short Metakaolin-red mud/carbon nanotubes geopolymer nanocomposite: mechanical properties and structural studies
title_sort metakaolin red mud carbon nanotubes geopolymer nanocomposite mechanical properties and structural studies
topic geopolymer
metakaolin
red mud
MWCNT
nanocomposite
mechanical strength
url https://doi.org/10.1088/2053-1591/ac54d6
work_keys_str_mv AT hamidrezaahmadi metakaolinredmudcarbonnanotubesgeopolymernanocompositemechanicalpropertiesandstructuralstudies
AT gholamrezakhalaj metakaolinredmudcarbonnanotubesgeopolymernanocompositemechanicalpropertiesandstructuralstudies
AT abolhassannajafi metakaolinredmudcarbonnanotubesgeopolymernanocompositemechanicalpropertiesandstructuralstudies
AT saloumehmesgariabbasi metakaolinredmudcarbonnanotubesgeopolymernanocompositemechanicalpropertiesandstructuralstudies
AT masumehsafari metakaolinredmudcarbonnanotubesgeopolymernanocompositemechanicalpropertiesandstructuralstudies