Abstracts Book - IMRC 2018

• SA6-P145
DESING AND CHARACTERIZATION OF A MICROWAVE CAVITY TO
CONTROL IRRADIATION OF CARBON NANOTUBES
Topacio Llarena Bravo 1 , Edgar Alvarez Zauco 1
1 Universidad Nacional Autónoma de México, Facultad de Ciencias, Mexico.
In this work a novel resonance microwave cavity to control energy irradiation
onto large areas were designed.This cavity is capable to control modification or
functionalization of carbon nanostructures. Cavity works at the TE101transversal
electric mode with 2.45 GHz frequency. We propose the Maxwell equations for
modeling propagation of these waves to solve them. It suppose an
approximation of an square potential without a source providing an analytical
expression, this approximation has an experimental deviation about 10%, due
to the real the dimensions of cavity and the elements inside, because of that its
characterization was necessary. This cavity was characterized with a netanalyzer,
finding a maximum electric field area inside the cavity. The intensity of
this electric field was tested with a luminous intensity of a NE-2 gas discharge
lamp, obtaining the electric energy supplied at different positions. Carbon
Nanotubes samples closed in Borosilicate reactors at 10 -3 Torr were irradiated.
After irradiation solubility tests were performed, obtaining little changes in their
structure. In order to understand those changes, Raman analysis were carried
out. Rate between D and G band intensity of Raman spectra shown the electric
energy range were the graphitization of CNT is maxima. For CNT samples
irradiated into a hydrogen peroxide atmosphere, the oxidation of CNT is
maxima at the same electric energy range. Those results revealed the existence
of an energy range when the magnetron system is applied between 56 % and
74 % when the 100% is 150V. This range also exposed that at 60% of the voltage
the optima modification of the NTC is expressed. For both types of samples, CNT
structure is preserved, supported by Scanning Electron Microscopy. This
method generates a solvent-free process, as well as a substantial decrease in
the reaction time, placing it within the parameters of green chemistry, which has
a direct and very important impact on environment by not generating polluting
residues.
Acknowledgment:
Authors will thank to, Dr Hugo Martin Sobral for the support on optical
characterization, to LUCE for Raman Spectroscopy, Dr. Cesar Leonardo Ordoñez