Effect of Carbon Nanotubes’ Diameter on Freeze-Thaw Resistance of Cement Paste

2020 ◽  
Vol 36 (4) ◽  
pp. 437-449
Author(s):  
Wei Tian ◽  
Fangfang Gao
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Cement Paste ◽  
Microstructural Analysis ◽  
Optimal Size ◽  
Multiwalled Carbon ◽  
Freeze Thaw ◽  
20 Nm

ABSTRACTThis paper aims to investigate the freeze-thaw resistance of cement-paste containing with different diameter and content of multiwalled carbon nanotubes (MWCNTs) in terms of mechanical properties and microstructure. Three groups of cement-paste with MWCNTs diameter of 10-20 nm, 20-40 nm and 40-60 nm were prepared by incorporating 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt% MWCNTs by cement weight. Experimental results showed that the addition of 0.1 wt% MWCNTs with diameters of 10–20 nm effectively improved the freeze-thaw resistance of cement-paste. In addition, microstructural analysis of these cement-paste specimens showed that MWCNTs addition increased the materials’ initial porosity, but a proper amount of MWCNTs decreased the porosity of cement-paste after freeze-thaw cycles and effectively improved the pore size distribution. MWCNTs 10–20 nm in diameter were found to be the optimal size for improving the microstructure of these MWCNTs cement-paste

The Effect of Surface Area, Pore Volume, and Pore Size Distribution on the Modified Multiwalled Carbon Nanotubes

2014 ◽  
Vol 625 ◽  
pp. 148-151 ◽  
Author(s):  
Rahmam Syuhaidah ◽  
Muti Mohamed Norani ◽  
Suriati Sufian
Keyword(s):  
Carbon Nanotubes ◽  
Surface Treatment ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Multiwalled Carbon Nanotubes ◽  
Pore Volume ◽  
Multiwalled Carbon ◽  
Effect Of Surface

Carbon Nanotubes (CNT) have emerged and gained great interest for research in many applications because of their unique specific characteristics such as having high porosity, high surface area and the existence of a wide spectrum of surface functional groups through chemical modification. Multiwalled carbon nanotubes (MWCNT) is a type of CNT that comprises of multiple layers of concentric cylinders. The overall study of this research work is to modify MWCNT to become a good adsorbent that can adsorb CO2 at its optimum capacity. In order to make MWCNT as an efficient adsorbent, surface treatment on pristine MWCNT is necessary to overcome the hydrophobicity issue by the introduction of carboxyl group. Upon the surface treatment, functionalization of MWCNT with 3-Aminopropyl triethoxysilane (APTS) was conducted to obtain the attachment of amine group that will assist MWCNT in adsorbing CO2. The surface treatment and functionalization process undergone by MWCNT changed the physical properties of MWCNT such as the surface area, pore volume, and pore size distribution. These properties can be determined using surface area and pore analyzer (SAP). Sample that treated with the mixture of nitric and sulfuric acid (HNO3/H2SO4) and functionalized with APTS gives the lowest surface area (22.07 m2/g) and pore volume (0.06 cm3/g). The pore size distribution also decreases due to the most presence of functional group onto the surface of modified MWCNT. This research paper is focusing on the effect of surface area, pore volume, and pore size distribution on the modified MWCNT.

Effect of Multiwalled Carbon Nanotubes On Mechanical Properties of Concrete

2012 ◽  
Vol 2 (6) ◽  
pp. 166-168 ◽  
Author(s):  
Dr.T.Ch.Madhavi Dr.T.Ch.Madhavi ◽  
◽  
Pavithra.P Pavithra.P ◽  
Sushmita Baban Singh Sushmita Baban Singh ◽  
S.B.Vamsi Raj S.B.Vamsi Raj ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon

scholarly journals Strength and Microscopic Damage Mechanism of Yellow Sandstone with Holes under Freezing and Thawing

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Huren Rong ◽  
Jingyu Gu ◽  
Miren Rong ◽  
Hong Liu ◽  
Jiayao Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Pore Size ◽  
Power Function ◽  
Damage Mechanism ◽  
Uniaxial Compression Test ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Microscopic Damage

In order to study the damage characteristics of the yellow sandstone containing pores under the freeze-thaw cycle, the uniaxial compression test of saturated water-stained yellow sandstones with different freeze-thaw cycles was carried out by rock servo press, the microstructure was qualitatively analyzed by Zeiss 508 stereo microscope, and the microdamage mechanism was quantitatively studied by using specific surface area and pore size analyzer. The mechanism of weakening mechanical properties of single-hole yellow sandstone was expounded from the perspective of microstructure. The results show the following. (1) The number of freeze-thaw cycles and single-pore diameter have significant effects on the strength and elastic modulus of the yellow sandstone; the more the freeze-thaw cycles and the larger the pore size, the lower the strength of the yellow sandstone. (2) The damage modes of the yellow sandstone containing pores under the freeze-thaw cycle are divided into five types, and the yellow sandstone with pores is divided into two areas: the periphery of the hole and the distance from the hole; as the number of freeze-thaw cycles increases, different regions show different microscopic damage patterns. (3) The damage degree of yellow sandstone is different with freeze-thaw cycle and pore size. Freeze-thaw not only affects the mechanical properties of yellow sandstone but also accelerates the damage process of pores. (4) The damage of the yellow sandstone by freeze-thaw is logarithmic function, and the damage of the yellow sandstone is a power function. The damage equation of the yellow sandstone with pores under the freezing and thawing is a log-power function nonlinear change law and presents a good correlation.

Mechanical Properties Of Polyaniline / Multi-walled Carbon Nanotube Composite Films

2003 ◽  
Vol 791 ◽  
Author(s):  
P. C. Ramamurthy ◽  
W. R. Harrell ◽  
R. V. Gregory ◽  
B. Sadanadan ◽  
A. M. Rao
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Composite Films ◽  
Weight Percent ◽  
Organic Electronic Devices ◽  
Multiwalled Carbon ◽  
Multi Walled Carbon Nanotube ◽  
Contact Devices ◽  
Carbon Nanotube Composite

ABSTRACTHigh molecular weight polyaniline / multi-walled carbon nanotube composite films were fabricated using solution processing. Composite films with various weight percentages of multiwalled carbon nanotubes were fabricated. Physical properties of these composites were analyzed by thermogravimetric analysis, tensile testing, and scanning electron microscopy. These results indicate that the addition of multiwalled nanotubes to polyaniline significantly enhances the mechanical properties of the films. In addition, metal–semiconductor (composite) (MS) contact devices were fabricated, and it was observed that the current level in the films increased with increasing multiwalled nanotube content. Furthermore, it was observed that polyaniline containing one weight percent of carbon nanotubes appears to be the most promising composition for applications in organic electronic devices.

Mechanical properties of poly(lactic acid)/multiwalled carbon nanotubes nanocomposites

2014 ◽  
Vol 18 (sup6) ◽  
pp. S6-14-S6-17 ◽  
Author(s):  
M. S. Z. Mat Desa ◽  
A. Hassan ◽  
A. Arsad ◽  
N. N. B. Mohammad
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Lactic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Poly Lactic Acid ◽  
Multiwalled Carbon

Thermal and mechanical properties of a nanocomposite of a photocurable epoxy-acrylate resin and multiwalled carbon nanotubes

2011 ◽  
Vol 528 (13-14) ◽  
pp. 4318-4324 ◽  
Author(s):  
Marcos N. dos Santos ◽  
Carlos V. Opelt ◽  
Fernando H. Lafratta ◽  
Carlos M. Lepienski ◽  
Sérgio H. Pezzin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Epoxy Acrylate ◽  
Thermal And Mechanical Properties ◽  
Multiwalled Carbon ◽  
Acrylate Resin ◽  
Epoxy Acrylate Resin
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