@MastersThesis{Marques:2015:CoTeNa,
author = "Marques, Vagner Eduardo Caetano",
title = "Comp{\'o}sitos termor{\'{\i}}gidos com nanotubos de carbono
verticalmente alinhados crescidos sobre a fibra de carbono",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2015",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2015-04-24",
keywords = "nanotubos de carbono, fibra de carbono, nanocomp{\'o}sitos,
catalisador flutuante, carbon nanotubes, carbon fiber,
nanocomposites, floating catalyst.",
abstract = "A presente disserta{\c{c}}{\~a}o consiste no estudo de
nanocomp{\'o}sitos feitos a partir da deposi{\c{c}}{\~a}o de
nanotubos de carbono verticalmente alinhados sobre tecidos de
fibras de carbono e sua posterior impregna{\c{c}}{\~a}o com
resina ep{\'o}xi, com a finalidade de melhorar as propriedades
mec{\^a}nicas interlaminares de comp{\'o}sitos com fibra de
carbono. O maior desafio deste trabalho foi a
otimiza{\c{c}}{\~a}o e o escalonamento do processo de
deposi{\c{c}}{\~a}o dos nanotubos de carbono para permitir
amostras extensas suficientes para confec{\c{c}}{\~a}o dos
corpos de prova de comp{\'o}sitos estruturais. Foi desenvolvida
uma forma de uniformizar a deposi{\c{c}}{\~a}o de uma
intercamada de sil{\'{\i}}cio amorfo (depositado por plasma DC
de silano), que serve como barreira de difus{\~a}o de ferro. O
ferro {\'e} o material utilizado na forma de nano
part{\'{\i}}culas como catalisador da nuclea{\c{c}}{\~a}o do
crescimento de materiais graf{\'{\i}}ticos. Esta camada de
sil{\'{\i}}cio amorfo foi, tamb{\'e}m, utilizada como interface
CNT/resina que nos permitiu obter resposta ao cisalhamento
interlaminar e um ganho nas propriedades el{\'e}tricas. Foi
utilizada a t{\'e}cnica Deposi{\c{c}}{\~a}o Qu{\'{\i}}mica de
Vapor em um forno tubular para os crescimentos dos nanotubos de
carbono. Ensaios de tra{\c{c}}{\~a}o tamb{\'e}m foram
realizados nos feixe de fibras para certifica{\c{c}}{\~a}o de
que suas propriedades mec{\^a}nicas foram mantidas ap{\'o}s as
deposi{\c{c}}{\~o}es realizadas. Para diversas etapas do
processo, foram produzidas amostras de comp{\'o}sito atrav{\'e}s
dos m{\'e}todos infus{\~a}o/inje{\c{c}}{\~a}o com baixas
press{\~o}es em moldes fechados. Foi realizada an{\'a}lise
morfol{\'o}gica e estrutural, atrav{\'e}s de Microscopia
Eletr{\^o}nica de Varredura e Espectroscopia Raman. Na
caracteriza{\c{c}}{\~a}o mec{\^a}nica, foram feitos testes de
DMA e cisalhamento interlaminar (norma ASTM 2344), e as fraturas
dos corpos de prova foram analisadas atrav{\'e}s de Microscopia
{\'O}ptica. O ganho no comportamento el{\'e}trico, conseguido
tanto pelos nanotubos quanto pela camada de Si amorfo, foi
determinado pelo M{\'e}todo de duas pontas para medida de
resistividade DC. Foi obtida a resistividade el{\'e}trica dos
comp{\'o}sitos tanto na dire{\c{c}}{\~a}o paralela aos tecidos
de fibra de carbono quanto na dire{\c{c}}{\~a}o perpendicular.
ABSTRACT: This dissertation is the study of nanocomposites made
from the deposition of vertically aligned carbon nanotubes on
carbon fibers cloths and subsequent impregnation with epoxy resin,
in order to improve the interlaminar mechanical properties of
carbon fiber composites. The biggest challenge of this work was
the optimization and scaling up of carbon nanotubes deposition
process to allow samples sufficiently extensive for the
fabrication of structural composites specimens. A way for uniform
deposition of an amorphous silicon interlayer was developed
(deposited by DC plasma of Silane), which serves as a diffusion
barrier to iron. The iron is used as catalyst nanoparticles for
growth of graphitic materials. This amorphous silicon layer was
also used as CNT/resin interface which allowed us a response to
the interlaminar shear and a gain on the electrical properties.
Chemical vapor deposition technique has been used in a tubular
furnace for growth of carbon nanotubes. Tensile strength tests
were also carried out on the fiber tow to certification that their
mechanical properties were maintained after the depositions
process. Composite samples for the several process steps were
produced by the infusion/injection methods at low pressures at
closed molds. Morphological and structural analysis were
performed, through scanning electron microscopy and Raman
spectroscopy. In mechanical characterization, DMA and interlaminar
shear tests were performed (standard ASTM 2344), and the fractures
of the specimens were analyzed by optical microscopy. The gain in
the electrical behavior, achieved by the nanotubes and by the
amorphous Si layer, was determined by the method of two points DC
resistivity measurement. The electrical resistivity of the
composites was obtained both in the parallel direction to the
carbon fiber cloth and in the perpendicular direction.",
committee = "Corat, Evaldo Jos{\'e} (presidente/orientador) and Antunes, Erica
Freire (orientador) and Machado, Jo{\~a}o Paulo Barros and Lobo,
Anderson de Oliveira",
copyholder = "SID/SCD",
englishtitle = "Thermoset composite with carbon nanotubes vertically aligned grown
on carbon fiber",
language = "pt",
pages = "119",
ibi = "8JMKD3MGP3W34P/3JCA8KE",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3JCA8KE",
targetfile = "publicacao.pdf",
urlaccessdate = "28 mar. 2024"
}