scholarly journals Thermal response characterization and comparison of carbon nanotube-enhanced cementitious composites

2018 ◽  
Vol 202 ◽  
pp. 1042-1050 ◽  
Author(s):  
Heeyoung Lee ◽  
Young Min Song ◽  
Kenneth J. Loh ◽  
Wonseok Chung
Keyword(s):  
Carbon Nanotube ◽  
Thermal Response ◽  
Cementitious Composites

Electromagnetic wave shielding/absorption performances of cementitious composites incorporating carbon nanotube metamaterial with helical chirality

2020 ◽  
Vol 54 (25) ◽  
pp. 3857-3870 ◽  
Author(s):  
Linwei Li ◽  
Sufen Dong ◽  
Xufeng Dong ◽  
Xun Yu ◽  
Baoguo Han
Keyword(s):  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Electromagnetic Wave ◽  
Carbon Nanotube ◽  
Cementitious Composites ◽  
Shielding Effectiveness ◽  
Electron Conduction ◽  
Helical Carbon Nanotubes ◽  
Percolation Zone ◽  
Helical Chirality

Helical carbon nanotubes, a type of chiral metamaterial, were employed to investigate their effects as well as the mechanisms to electromagnetic wave shielding and absorption performances of cementitious composites over the frequency range from 2 GHz to 18 GHz. The results demonstrate that the best electromagnetic wave shielding effectiveness (SE) of cementitious composites filled with 7.5 wt.% helical carbon nanotubes is 1.39 times of that of cementitious composites without helical carbon nanotubes. The minimum reflectivity in 20 mm-thickness cementitious composites with 4.5 wt.% helical carbon nanotubes is 2.7 times of that of cementitious composites without helical carbon nanotubes. Cementitious composites with 7.5 wt.% helical carbon nanotubes have smallest matching thickness and the minimum reflectivity of −41.0 dB. By analyzing electromagnetic parameters and conductive mechanisms, it is found that helical carbon nanotubes mainly affect reflection loss ratio in electromagnetic wave shielding and the dielectric loss in electromagnetic wave absorption. Both parameters are attributed to the enhanced conductivity with the increase of helical carbon nanotubes. The percolation zone ranges from 1.5 wt.% to 7.5 wt.% for alternating current resistivity, with conductive path transferring from ion conduction to electron conduction as the content of helical carbon nanotubes increases. Additionally, incorporating helical carbon nanotubes essentially does not cause the decrease in compressive strength of cementitious composites. The results recommend that cementitious composites incorporating carbon nanotube metamaterial with helical chirality present high electromagnetic performances with satisfactory compressive strength.

Microscopy investigations of the microstructural change and thermal response of cobalt-based nanoparticles confined inside a carbon nanotube medium

2015 ◽  
Vol 3 (21) ◽  
pp. 11203-11214 ◽  
Author(s):  
Walid Baaziz ◽  
Ileana Florea ◽  
Simona Moldovan ◽  
Vasiliki Papaefthimiou ◽  
Spyridon Zafeiratos ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Carbon Nanotube ◽  
Thermal Response ◽  
Microstructural Change

In this work, we investigate the shape, microstructure and thermal response upon heat treatment of Co-based NPs inside CNTs.

Graphene oxide-assisted multi-walled carbon nanotube reinforcement of the transport properties in cementitious composites

2019 ◽  
Vol 55 (2) ◽  
pp. 603-618 ◽  
Author(s):  
Yuan Gao ◽  
Hongwen Jing ◽  
Zefu Zhou ◽  
Weiqiang Chen ◽  
Luan Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Carbon Nanotube ◽  
Transport Properties ◽  
Cementitious Composites ◽  
Multi Walled Carbon Nanotube
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