Multiscale pore structure analysis of nano titanium dioxide cement mortar composite

Research output: Contribution to journalArticle

Abstract

The effects of nano-Ti O2(NT) on the multiscale pore system and morphology of cement mortars were studied by X-ray computed tomography (X-CT), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) method. The obtained results from X-CT showed that microscale pores (from 20 μm to 200 μm) of mortars mixed with 2.5 wt% NT were significantly refined. When the content of NT is more than 2.5 wt%, the total pore volume and the number of pores begin to increase. However, when the amount of NT exceeds the optimal value, e.g., (2.5 < NT < 5%), the recorded 2D porosity (void area fraction), are still lower than the reference sample. Meanwhile, the microscopy results proved that, by adding 2.5 wt% NT, the pores of cement mortars were best filled, resulting in a more homogenous morphology. At the nanoscale, the BET results revealed a clear trend of increasing surface area and pore volume of the NT cement mortars, over the entire range of NT percentages, i.e., from 0 wt% to 10 wt%. This could stem from the formation of nanosized needle-shaped products in the presence of the nanoparticles. Further, the permeability of NT cement mortars was measured using a high-pressure core holder and the results showed that 2.5 wt% NT inclusions could reduce the permeability of the cement mortars by 32%. However, adding more NT (>2.5 wt.%) led to higher permeability. This is in line with the microscale pore analysis from X-CT. It can be concluded that adding a certain amount of NT (around 2.5 wt%) can modify the pore structure of cement mortars by changing the harmful microscale pores (permeability related) to the nano-sized benign pores, leading to a much stronger durability of cement-based materials.
Original languageEnglish
Article number100779
Number of pages10
JournalMaterials Today Communications
Volume22
Early online date18 Nov 2019
DOIs
Publication statusE-pub ahead of print - 18 Nov 2019

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Pore structure
Mortar
Titanium dioxide
Tomography
Cements
X rays
Composite materials
Durability
Scanning electron microscopy
titanium dioxide

Keywords

  • Brunauer-Emmett-Teller (BET)
  • nano titanium dioxide (NT)
  • permeability
  • scanning electron microscopy (SEM)
  • X-ray computed tomography (X-CT)

Cite this

@article{c1a8dd076c6944308bb14797861bda0a,
title = "Multiscale pore structure analysis of nano titanium dioxide cement mortar composite",
abstract = "The effects of nano-Ti O2(NT) on the multiscale pore system and morphology of cement mortars were studied by X-ray computed tomography (X-CT), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) method. The obtained results from X-CT showed that microscale pores (from 20 μm to 200 μm) of mortars mixed with 2.5 wt{\%} NT were significantly refined. When the content of NT is more than 2.5 wt{\%}, the total pore volume and the number of pores begin to increase. However, when the amount of NT exceeds the optimal value, e.g., (2.5 < NT < 5{\%}), the recorded 2D porosity (void area fraction), are still lower than the reference sample. Meanwhile, the microscopy results proved that, by adding 2.5 wt{\%} NT, the pores of cement mortars were best filled, resulting in a more homogenous morphology. At the nanoscale, the BET results revealed a clear trend of increasing surface area and pore volume of the NT cement mortars, over the entire range of NT percentages, i.e., from 0 wt{\%} to 10 wt{\%}. This could stem from the formation of nanosized needle-shaped products in the presence of the nanoparticles. Further, the permeability of NT cement mortars was measured using a high-pressure core holder and the results showed that 2.5 wt{\%} NT inclusions could reduce the permeability of the cement mortars by 32{\%}. However, adding more NT (>2.5 wt.{\%}) led to higher permeability. This is in line with the microscale pore analysis from X-CT. It can be concluded that adding a certain amount of NT (around 2.5 wt{\%}) can modify the pore structure of cement mortars by changing the harmful microscale pores (permeability related) to the nano-sized benign pores, leading to a much stronger durability of cement-based materials.",
keywords = "Brunauer-Emmett-Teller (BET), nano titanium dioxide (NT), permeability, scanning electron microscopy (SEM), X-ray computed tomography (X-CT)",
author = "Davood Shafaei and Shangtong Yang and Leonard Berlouis and James Minto",
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Multiscale pore structure analysis of nano titanium dioxide cement mortar composite. / Shafaei, Davood; Yang, Shangtong; Berlouis, Leonard; Minto, James.

In: Materials Today Communications, Vol. 22, 100779, 31.03.2020.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Multiscale pore structure analysis of nano titanium dioxide cement mortar composite

AU - Shafaei, Davood

AU - Yang, Shangtong

AU - Berlouis, Leonard

AU - Minto, James

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N2 - The effects of nano-Ti O2(NT) on the multiscale pore system and morphology of cement mortars were studied by X-ray computed tomography (X-CT), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) method. The obtained results from X-CT showed that microscale pores (from 20 μm to 200 μm) of mortars mixed with 2.5 wt% NT were significantly refined. When the content of NT is more than 2.5 wt%, the total pore volume and the number of pores begin to increase. However, when the amount of NT exceeds the optimal value, e.g., (2.5 < NT < 5%), the recorded 2D porosity (void area fraction), are still lower than the reference sample. Meanwhile, the microscopy results proved that, by adding 2.5 wt% NT, the pores of cement mortars were best filled, resulting in a more homogenous morphology. At the nanoscale, the BET results revealed a clear trend of increasing surface area and pore volume of the NT cement mortars, over the entire range of NT percentages, i.e., from 0 wt% to 10 wt%. This could stem from the formation of nanosized needle-shaped products in the presence of the nanoparticles. Further, the permeability of NT cement mortars was measured using a high-pressure core holder and the results showed that 2.5 wt% NT inclusions could reduce the permeability of the cement mortars by 32%. However, adding more NT (>2.5 wt.%) led to higher permeability. This is in line with the microscale pore analysis from X-CT. It can be concluded that adding a certain amount of NT (around 2.5 wt%) can modify the pore structure of cement mortars by changing the harmful microscale pores (permeability related) to the nano-sized benign pores, leading to a much stronger durability of cement-based materials.

AB - The effects of nano-Ti O2(NT) on the multiscale pore system and morphology of cement mortars were studied by X-ray computed tomography (X-CT), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) method. The obtained results from X-CT showed that microscale pores (from 20 μm to 200 μm) of mortars mixed with 2.5 wt% NT were significantly refined. When the content of NT is more than 2.5 wt%, the total pore volume and the number of pores begin to increase. However, when the amount of NT exceeds the optimal value, e.g., (2.5 < NT < 5%), the recorded 2D porosity (void area fraction), are still lower than the reference sample. Meanwhile, the microscopy results proved that, by adding 2.5 wt% NT, the pores of cement mortars were best filled, resulting in a more homogenous morphology. At the nanoscale, the BET results revealed a clear trend of increasing surface area and pore volume of the NT cement mortars, over the entire range of NT percentages, i.e., from 0 wt% to 10 wt%. This could stem from the formation of nanosized needle-shaped products in the presence of the nanoparticles. Further, the permeability of NT cement mortars was measured using a high-pressure core holder and the results showed that 2.5 wt% NT inclusions could reduce the permeability of the cement mortars by 32%. However, adding more NT (>2.5 wt.%) led to higher permeability. This is in line with the microscale pore analysis from X-CT. It can be concluded that adding a certain amount of NT (around 2.5 wt%) can modify the pore structure of cement mortars by changing the harmful microscale pores (permeability related) to the nano-sized benign pores, leading to a much stronger durability of cement-based materials.

KW - Brunauer-Emmett-Teller (BET)

KW - nano titanium dioxide (NT)

KW - permeability

KW - scanning electron microscopy (SEM)

KW - X-ray computed tomography (X-CT)

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DO - 10.1016/j.mtcomm.2019.100779

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