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CVD of CNFs, MW-, DW-, and SW-Nanotubes

 

Synthesis, characterization, application

Carbon nanotubes (CNTs), a material with unique electrical, mechanical, thermal, and chemical properties, have attracted much attention for various technological applications such as functional components for electronic nanodevices, as additives for polymer composites, and as electrode materials.

Depending on the number of tube walls, CNTs can be assigned to single-walled (SW), double-walled (DW), and multi-walled (MW) nanotubes. Carbon nanofibers (CNFs) of the type "herringbone" and "platelet" (diameter >100 nm) do show interesting chemical and physical properties, they are  promising candidates for additions to different composite materials.

The catalytic CVD using metal particles as catalyst is the mostly used method for the CNT synthesis with high controllability of the NT structure and diameter and quite versatile for scaled-up production of CNTs.

The CVD group of the IFF is engaged in synthesis and characterization of carbon nanostructures as bulk, layer, or in individual materials, using thermal catalytic and plasma enhanced CVD methods.  The topics are focussed on investigation of growth  mechanism, structure, and catalytic effects with the aim to improve the material regarding uniformity of structure, diameter, and length as well as impurity content.

 

Activities:

1. Synthesis of CNTs with controllable diameter range using the "fixed bed" method: 

Figure0.gif

Scheme of CVD reactor with solid catalyst material

 

Dependence of CNT-type on the metal concentration inside of catalyst

01_SW-Bundles.jpg

SWbundles

([Me]<1 wt.%)

02_SW_DW.jpg

SW/DWCNTs

([Me]~1 wt.%)

 

03_DW.jpg

DWCNTs

([Me]~4 wt.%)

04_FWNT.jpg

FWCNTs (6 shells)

([Me]~16 wt.%)

05_MWNT.jpg

MWCNTs (20 shells)

([Me]~25 wt.%)


 

2. Synthesis of CNTs with defined narrow diameter distribution

using the "aerosol" CVD

 

 

Ae_CVD_bundles.jpg

Aligned growth

 MWNT_Ndoped1.JPG

Bamboo-like structure by nitrogen doping

 MWNT_Ndoped2.JPG

Transversal shells by nitrogen-doping

 Ae_tip.gif

Tip-growth (typical Fe-catalysts)


 

3. Synthesis of type-pure CNFs (herringbones, platelets) by fixed-bed CVD

CNF/herringbones

 Herri2.jpg

CNF_herri1.gif

CNF_herri2.jpg

 

 CNF/platelets

 Plate1.jpg

CNF_plate1a.gif CNF_plate2.jpg
 

  

For more information don't hesitate to contact.

Contacts:

Dr. Albrecht Leonhardt
Department 'Chemical Vapor Deposition'
Institute for Solid State Research (IFF)
IFW Dresden
D-01171 Dresden, Germany

Phone: +49-351-4659-299
Fax: +49-351-4659-440

Email: a.leonhardt@ifw-dresden.de

 


See also:

Initial page of department CVD

Head of Department

Dr. Albrecht Leonhardt

IFW Dresden
Institute for Solid State Research (IFF)
Dpt. Chemical Vapour Deposition (CVD)
P.O. Box 27 00 16
D-01171 Dresden, Germany

Phone: -49/351/4659-299
Fax: -49/351/4659-313
Email: a.leonhardt@ifw-dresden.de