InterAmerican Materials Collaboration: Large Scale Synthesis of Ndoped Carbon Nanotubes for the Fabr

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Inter-American Materials Collaboration Large
Scale Synthesis of N-doped Carbon Nanotubes for
the Fabrication of Novel Polymer Composites and
Related Low Dimensional MaterialsPulickel M.
Ajayan, Rensselaer Polytechnic Institute,
DMR-0303174
Carbon nanotube heterojunctions Continuous
bi-phasic nanotubes were synthesized using
chemical vapor deposition (CVD) using two sources
of hydrocarbon precursors and vapor phase
catalyst (ferrocene) delivery. The nanotube (NT)
/ nitrogen doped nanotube (CNx) junctions were
made by the two-step feeding process. First,
xylene/ferrocene was fed to grow CNTs. Then,
xylene/ dimethylfamamide (DMF) / ferrocene was
fed to grow CNx. The CNx grows from the catalyst
particles previously present on the NT films
grown in the prior sequence. Contiguous NT/CNx
junction are thus created efficiently. Electron
microscopy (TEM) revealed that the CNx nanotubes
showed different internal structure and
morphology compared to NT, with a bamboo-like
structure for the former.
Shematic showing the CVD furnace (top) with two
different hydrocarbon precursors. The nanotubes
with junctions of pure NT and CNx grows
vertically on the quartz substrates placed inside
the furnace (bottom schematic). TEM image (top
right) shows the bamboo morphology of CNx
nanotubes (Scale bar is 100 nm)
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Inter-American Materials Collaboration Large
Scale Synthesis of N-doped Carbon Nanotubes for
the Fabrication of Novel Polymer Composites and
Related Low Dimensional MaterialsPulickel M.
Ajayan, Rensselaer Polytechnic Institute,
DMR-0303174
Outreach The program supported a high school
student (Manisha Padi from Niskayuna high school,
close to RPI) to spend considerable amount of
time in our laboratory, both during the summer of
2004 and 2005 and part time during the academic
year. She completed significant amount of work on
the electrodeposition of magnetic nanowires in
porous alumina templates and has been trained on
several instrumentation in the laboratory. She
will co-author a full research paper, which will
be submitted to a peer reviewed journal. In
July 2004, we (PIs from RPI and IPICyT) organized
a joint international conference in Mexico
(Nanotube 04) which was attended by well over 300
attendees from around the world and was a great
success. NSF, CONACYT, and Industry had strong
participation at the conference and was attended
by several students from the Latin American
countries.
Education and Training The project provided
excellent opportunities for student exchanges and
training between RPI and IPICyT in Mexico. Three
Mexican undergraduate student visitors who spent
brief durations of time at RPI, completed their
courses in Mexico and received admissions to
prestigious international universities for
graduate study Federico Villalpado was admitted
to graduate study at MIT, Felipe Cervantes Sodi
and Juan-Jose Vilatela-Garcia, both got admission
to Cambridge University in England. Another
Mexican graduate student visitor, Ana Laura Elias
Arriaga has returned to RPI for the second time
and is presently staying at RPI to complete her
thesis work. Several graduate students in our
laboratory worked with these visiting students
from Mexico and the collaboration was mutually
beneficial for students from both sides. The
visiting students received training on all the
nanotube synthesis facilities and the microscopy
and scanning probe microscopy facilities at RPI.