153Nanosensor Laboratory
form of amorphous carbon and catalyst particles because of the high tem-
perature nature of the heat source. Since the growth is difcult to control, the
nal product consists mostly of multi-walled carbon nanotubes (MWCNTs)
with poor alignment. Nonetheless, the overall yield of CNTs produced is
sufcient for laboratory-scale experiments and they have been mostly used
for academic research.
What is the favorite technique for CNT manufacturing? It is CVD. What is CVD?
CVD involves irreversible deposition of a solid from a gas or a mixture of
gases through a heterogeneous chemical reaction. Where does this reaction
occur? It takes place at the interface of gas–solid substrate. Depending on the
deposition conditions, ...