Universität Wien

Preparation of Nanomaterials

TEM from solution filled peapod, Simon et al. CPL 2004

Filling of single wall carbon nanotubes (SWCNTs)

Various techniques are used to fill SWCNTs. The conditions for optimum filling are a central part of the research work.
A) Filling from vapor phase: particularly for fullerenes, need tubes with appropriate holes and 500°C reaction temperature
B) Filling from solution: for fullerenes or other molecules needs tubes with holes but only 70°C reaction temperature
C) Filling from melt: for semiconductors or ionic crystals no special etching for tube opening required needs temperatures just above melting point
Analysis of filling by TEM, EELS or Raman. A smart way to check filling in case of carbon material is the recording of the Raman response after transformation to DWCNTs

Calibration curve for determination of pea concentration, Kuzmany et al. EPJ 2003

TEM from melt filled PbO@SWCNT, Hulman et al. APL 2003

Doping of tubular material

Fullerenes, SWCNTs, peapods and DWCNTs can be intercalated with electron donors (for tubes also electron acceptors) by heating the material in corresponding vapor. Phonons exhibit characteristic shifts in self energy.

In the case of n-doping of peapods the alkali metal was suggested to settle inside the tubes

Shift of pentagonal pinch mode with charge on C60

Selforganization of functioalized molecules

Functionalized fullerenes order on casting from solution into alligned nanorods. After stripping off the functional groups the fullerenes polymerize

Decoration of metallic colloids with molecules

SERS Raman spectrum of SWCNTs on Ag colloids
a) SERS spectrum of SWCNTs
b) Spectrum without SERS enhancement
c) 100 x blow up of b)