Indentation Response of Nanostructured Turfs

2007 ◽  
Vol 1049 ◽  
Author(s):  
A. A. Zbib ◽  
S. Dj. Mesarovic ◽  
D. F. Bahr ◽  
E. T. Lilleodden ◽  
J. Jiao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Vapor Deposition ◽  
Permanent Deformation ◽  
Compressive Loading ◽  
Chemical Vapor ◽  
Contact Loading ◽  
Buckling Stress ◽  
Aspect Ratios ◽  
Applied Stresses ◽  
Indentation Response

AbstractWhen grown via chemical vapor deposition carbon nanotubes (CNTs) may take on the form of a “turf”, consisting of many CNTs with a complex interconnectedness attached to an inflexible substrate. These turfs can be formed over large areas and with a range of heights (between 1 to 100 μm), and grown on photolithographically patterned catalysts to form different aspect ratios. This study focuses on the indentation and permanent deformation of CNT assemblages under applied contact loading. Nanoindentation was conducted on CNT turfs and the properties, nominally the turf's elastic modulus and hardness, were 14.9 MPa ± 5.7 MPa and 2 MPa respectively. The onset of permanent deformation during indentation occurred at applied stresses of 2.5 MPa. The turf's collective permanent deformation under applied compressive loading was also studied. A model predicting the buckling stress of CNT turfs is also described.

A Hierarchical Approach to Purify and Functionalize Pristine Carbon Nanotubes

2012 ◽  
Vol 510-511 ◽  
pp. 118-123
Author(s):  
M. Mansoor
Keyword(s):  
Carbon Nanotubes ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Wet Oxidation ◽  
Hierarchical Approach ◽  
Experimental Conditions ◽  
Aspect Ratios ◽  
Carbon Impurities ◽  
Metallic Catalyst ◽  
Surfactant Assisted

A step-by-step, hierarchical approach is explored in the present work to purify and functionalize carbon nanotubes synthesized by chemical vapor deposition. Attempts are made to purify and functionalize CNTs without extinguishing their aspect ratios. The carbon impurities are removed by thermal oxidation, whilst the unprotected metallic catalyst particles are eliminated by wet oxidation, subsequently; CNT bundles are de-roped by surfactant assisted sonication. Finally, protected metallic catalyst particles are removed and functional groups (hydroxyl and carboxyl) are attached by acid treatment and wet oxidation, respectively. The derivate CNTs are characterized using zeta potential measurements, TGA, XRD, FTIR and SEM. The characterization showed that in optimum experimental conditions the catalytic particles are removed upto 80%, the carbon impurities are eliminated upto 95% and chemical functionalities of hydroxyl and carboxyl is occurred with noticeable de-roping of the CNT bundles.

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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