Síntese e caracterização de nanocompósitos de ferrita de cobalto/carvão ativado à partir de copolímeros de estirenodivinilbenzeno sintetizados com óleo de soja
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2014-03-11
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Universidade Federal de Goiás
Resumo
In this work, activated carbon beads were prepared through
carbonization of styrene-divinylbenzene (Sty-DVB) copolymers synthesized
in the presence of soybean oil as diluent and cobalt ferrite nanoparticles
dispersed in the organic phase. Firstly, a cobalt ferrite gel was prepared
through co-precipitation technique with posterior surfactant action by oleic
acid. The copolymer and the composites containing cobalt ferrite were
obtained through suspension polymerization. Four matrixes were obtained,
which have the following differences: the cobalt ferrite content (2 or 5 %), the
amount of hydroxyethylcellulose used in the synthesis and the realization or
not of a purification step before thermal treatments. Soybean oil was chosen
as diluents in order to evaluate its effects on the synthesized materials
considering the polymerization possibility due fat acid unsaturations and its
low volatility. All synthesized materials were characterized by the following
analysis: DRX, FTIR, TGA, nitrogen adsorption measurements (specific
surface area, pore volume and pore size distribution), MEV and catalytic
activity in the ethyl-benzene dehydrogenation reaction. Further, the
composites had metal content evaluate by AAS. The soybean oil and the
ferrite gel had a strong influence on the textural properties of copolymers and
their respective activated carbons. All obtained activated carbons were active
in relation to ethylbenzene dehydrogenation reaction. However, the activated
carbon obtained from pure copolymer, i.e., without cobalt ferrite, presented
the highest specific surface area, catalytic activity and selectivity. This
catalyst also had the best stabilization of catalytic properties during evaluated
reaction time.
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BARBOSA, Carolina Freire. Síntese e caracterização de nanocompósitos de ferrita de cobalto/carvão ativado à partir de copolímeros de estirenodivinilbenzeno sintetizados com óleo de soja. 2014. 105 f. Dissertação (Mestrado em Química) Universidade Federal de Goiás, Goiânia, 2014.