Growth of Carbon Nanotubes in Calcium Phosphate Matrix with Different Ca/P Molar Ratio

2011 ◽  
Vol 688 ◽  
pp. 141-147 ◽  
Author(s):  
Xiao Ying Lu ◽  
Tian Qiu ◽  
Jie Yu Liu ◽  
Bao Hua Wu ◽  
Jie Weng
Keyword(s):  
Carbon Nanotubes ◽  
Calcium Phosphate ◽  
Vapor Deposition ◽  
Crystal Size ◽  
Chemical Vapor ◽  
Molar Ratio ◽  
Tube Length ◽  
Wall Surface ◽  
The Matrix ◽  
Walled Cnts

This paper reports that carbon nanotubes (CNTs) can be successfully grown from calcium phosphate matrix without additional catalysis of transition metal by chemical vapor deposition (CVD) using acetylene as carbon source. There is a great difference in the CNT growth from the matrix prepared with the different initial Ca/P molar ratio. The matrix prepared with lower initial Ca/P molar ratio is favorable for the growth of CNTs. A number of multi-walled CNTs with the diameter of 25~40 nm and 15~25 nm can be produced from the matrix with initial Ca/P molar ratio of 1.5 and 1.625, respectively, while no CNTs can be grown from the matrix with initial Ca/P molar ratio of 1.67. Tricalcium phosphate and hydroxyapatite crystallites with crystal size smaller than 50 nm besides carbon crystals are found in the as-obtained powders prepared with initial Ca/P molar ratio of 1.5 and 1.625. Compared with the growth of CNTs produced from all the matrixes, it is found that the CNTs grown from this matrix with Ca/P molar ratio of 1.5 have the longest tube length, cleanest and smoothest wall surface, and the content of CNTs is highest.

In Situ Growth of Carbon Nanotubes in Hydroxyapatite Matrix by Chemical Vapor Deposition

2009 ◽  
Vol 79-82 ◽  
pp. 1671-1674 ◽  
Author(s):  
Xiao Ying Lu ◽  
Hao Wang ◽  
Sheng Yi Xia ◽  
Jian Xin Wang ◽  
Jie Weng
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Biomedical Applications ◽  
Chemical Vapor ◽  
Novel Method ◽  
Biomedical Fields ◽  
Walled Cnts

Carbon nanotubes (CNTs)/hydroxyapatite (HA) nanocomposites have been successfully fabricated by a novel method for the biomedical applications, which is in situ growing CNTs in HA matrix in a chemical vapor deposition (CVD) system. The results show that it is feasible to in situ grow CNTs in HA matrix by CVD for the fabrication of CNTs/HA nanocomposites. Multi-walled CNTs with 50-80 nm in diameter have been grown in situ from HA matrix with the pretreatment of sintering at 1473K in air. The nanocomposites are composed with carbon crystals in CNTs form, HA crystallites and calcium phosphate crystallites, one of most important CaP bioceramics. And the CNTs content is about 1% proportion by weight among the composites in our experiments, which can enhance the HA mechanical properties and the CNTs content does not affect the HA performances. These CNTs/HA nanocomposites have the potential application in the biomedical fields.

DIRECT GROWTH OF MULTI-WALLED CARBON NANOTUBES ON SHARP TIPS FOR ELECTRON MICROSCOPY

NANO ◽  
2006 ◽  
Vol 01 (01) ◽  
pp. 35-39 ◽  
Author(s):  
M. MANN ◽  
K. B. K. TEO ◽  
W. I. MILNE ◽  
T. TESSNER
Keyword(s):  
Carbon Nanotubes ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Vertical Axis ◽  
Electron Sources ◽  
Multi Walled Carbon Nanotubes ◽  
Direct Growth ◽  
Walled Carbon Nanotubes ◽  
Excellent Stability ◽  
Walled Cnts

The favorable electron optical properties of carbon nanotubes (CNTs) have been studied in detail, but the application to electron sources has been limited by the complexity of the fabrication process. We report the use of Plasma Enhanced Chemical Vapor Deposition (PECVD) for the direct deposition of multi-walled CNTs onto the apex of sharply etched tungsten tips, aligned to the vertical axis of the tips. We show that these emitters have excellent stability.

Effect of Hydroxyapatite Matrix on the Growth of Carbon Nanotubes via a CVD System

2011 ◽  
Vol 685 ◽  
pp. 335-339 ◽  
Author(s):  
Xiao Ying Lu ◽  
Bao Hua Wu ◽  
Yu Jie Liu ◽  
Tian Qiu ◽  
Jie Weng
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fibers ◽  
Chemical Vapor ◽  
Weight Percent ◽  
The Matrix ◽  
Physical Mixing ◽  
Nano Size ◽  
Walled Cnts ◽  
Chemical Coprecipitation Method

This paper reports the fabrication of carbon nanotubes (CNTs) /hydroxyapatite (HA) composites via in-situ process in a chemical vapor deposition (CVD) system and the effect of HA matrix on the growth of CNTs. When the HA matrix is fabricated by a chemical coprecipitation method, deficient HA (D-HA) crystals in nano size have been observed in these composites. There are about 20% weight percent of multi-walled CNTs with a mean diameter of 40~60 nm. When the matrix used as catalyst for CNTs growth without HA in the same way, no CNTs but solid carbon fibers in submicrometer scale have been produced in these composites. Only Fe and MgO crystals can be observed in these composites. When the HA matrix is fabricated by a physical mixing with the presence of D-HA crystals, hollow CNTs with the diameter of 180~210 nm are also produced in these composites. Fe and MgO besides P2O5, D-HA and C crystals can be observed in the composites.

Cobalt supported on carbon nanotubes for methane chemical vapor deposition towards carbon nanotubes

2021 ◽  
Author(s):  
Laura Esteves ◽  
Hugo Alvarenga Oliveira ◽  
Y. T. Xing ◽  
Fabio Barboza Passos
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Heterogeneous Catalysis ◽  
Vapor Deposition ◽  
Supported Catalysts ◽  
Chemical Vapor

Carbon nanotubes (CNT) application in heterogeneous catalysis has been attracting growing interest. However, the use of CNT-supported catalysts in the chemical vapor deposition for the production of new CNT is...

Fabrication of short and straight carbon nanotubes by chemical vapor deposition

2008 ◽  
Vol 476 (1-2) ◽  
pp. 230-233 ◽  
Author(s):  
Haipeng Li ◽  
Naiqin Zhao ◽  
Chunnian He ◽  
Chunsheng Shi ◽  
Xiwen Du ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor
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