Synthesis and Functional Properties oc Carbon Nanotubes

Synthesis and Functional Properties of Carbon Nanotubes

Lichtbogenverfahren zur Darstellung von CNTs
Arc discharge system to produce CNTs.

Carbon nanotubes (CNTs) are a class of materials which suffer an increased scientific interest all over the world. Most attention is focused on the aligned synthesis of these materials in combination with their electronic and mechanic properties.Up to date there are three major synthetic approaches as there are arc discharge, laser ablation and chemical vapor deposition. All three methods are cracking carbonous materials (graphitic rods or various hydrocarbons) at high temperature producing small, highly reactive carbon fragments. These fragments will be soluted in catalytic particles building up tubular structures with graphene walls.

TEM micrograph of aligned CNTs synthesised via a CVD process.
TEM micrograph of aligned CNTs synthesised via a CVD process.

These molecular structure makes CNTs an interesting material for electronic as well as mechanical applications. The excelent electrical conductivity combined with an high aspect ration (ratio of length to diameter) makes CNTs a promissing candidate for field emission displays (FED) and field effect transistor (FET) (see Device Structures). The major step in an development of such applications is the aligned and controlled synthesis of CNTs. The past research activities have shown that a sufficient ordering of CNTs can only be reached by a CVD process, whereas arc discharge and laser ablation produce non aligned CNT powders. The major interest of our research activities in the field of CNT synthesis is focused on a production of aligned CNTs via a CVD process. Afterwards these aligned block arangements of CNTs can be used to produce various types of FED and FET arrangements. The properties of FEDs and FETs are controlled by various functionalisations and surface modifications of individual as well as block aranged tubes. Another field of interest using CNT functionalisation are the incorporation of CNTs in polymer matrices. CNTs are known for their high flexibility which makes them an interesting material for mechanical stabilisation of polymer structures. Here our main interest is focused on the interface between the CNT surface and polymer matrix. This gap of two different materials should be well understood to doped polymer structures with optimum strengh and flexibility.

Publications

  • Z. Allg. Anorg. Chem. (2008), 634, 911-915.
  • Small, (2007), 3 ,974 – 985.
  • NATO Science Series II (2006), 222, 63.
  • Z. Allg. Anorg. Chem. (2009), in press.
  • Solid State Sciences (2009), 11, 422-427.
  • Micro and Nanomaterials (2008), 8, 34-35.
  • Diamond. Rel. Mater. (2008), 17, 913-919.
  • Inorganica Chimica Acta (2008), 361, 1770-177.
  • Appl. Phys. A (2009), in press.