1 research outputs found
Versatile in Situ Gas Analysis Apparatus for Nanomaterials Reactors
We
report a newly developed technique for the in situ real-time
gas analysis of reactors commonly used for the production of nanomaterials,
by showing case-study results obtained using a dedicated apparatus
for measuring the gas composition in reactors operating at high temperature
(<1000 °C). The in situ gas-cooled sampling probe mapped the
chemistry inside the high-temperature reactor, while suppressing the
thermal decomposition of the analytes. It thus allows a more accurate
study of the mechanism of progressive thermocatalytic cracking of
precursors compared to previously reported conventional residual gas
analyses of the reactor exhaust gas and hence paves the way for the
controlled production of novel nanomaterials with tailored properties.
Our studies demonstrate that the composition of the precursors dynamically
changes as they travel inside of the reactor, causing a nonuniform
growth of nanomaterials. Moreover, mapping of the nanomaterials reactor
using quantitative gas analysis revealed the actual contribution of
thermocatalytic cracking and a quantification of individual precursor
fragments. This information is particularly important for quality
control of the produced nanomaterials and for the recycling of exhaust
residues, ultimately leading toward a more cost-effective continuous
production of nanomaterials in large quantities. Our case study of
multiwall carbon nanotube synthesis was conducted using the probe
in conjunction with chemical vapor deposition (CVD) techniques. Given
the similarities of this particular CVD setup to other CVD reactors
and high-temperature setups generally used for nanomaterials synthesis,
the concept and methodology of in situ gas analysis presented here
does also apply to other systems, making it a versatile and widely
applicable method across a wide range of materials/manufacturing methods,
catalysis, as well as reactor design and engineering