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Previous issue date: 2013-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In recent years, studies about the physicochemical properties of mixed oxides, call
attention of the scientific community, properties like as piezoelectricity, photoluminescence,
or applications as catalysts, arise in these compounds, when their chemical compositions are
modified, in this context some routes are employed in the synthesis of these materials, among
which can be cited these methods: ceramic, combustion, co-precipitation, Pechini or
polymeric precursor method, hydrothermal, sol-gel; these routes are divided into traditional
routes or chemical routes. In this work were synthesized oxides with variable composition,
from the thermal decomposition of titanium, cobalt, nickel and praseodymium
nitrilotriacetates. The nitrilotriacetates were characterized by IR Spectroscopy (FTIR),
Thermogravimetric (TG/ DTG) and Differential Scanning Calorimetry (DSC), while oxides
have been characterized by X-ray diffraction (XRD), Spectrofluorimetry and IR Spectroscopy
(FTIR). From FTIR data, it was demonstrated that the displacement of the band
corresponding to the carboxylate group (νCOOH) at 1712 cm-1, present in nitrilotriacetic acid
(H3NTA), for 1680-1545 cm-1, these stretches are characteristics of coordinated
nitrilotriacetates, By thermal analysis (TG/DTG /DSC), it was suggested, that in an oxidizing
atmosphere (air) oxides are obtained at lower temperatures than in an inert atmosphere N2(g).
By results from X-ray Diffraction (XRD), it was determinated that the oxides are crystalline
and the predominant phases obtained are summarized titanate phases rutile and ilmenite. By
fluorimetry was observed that the intensity of emission bands are directly proportional to the
concentration of ions Ni2+, Co2+ and Pr3+, and IR spectroscopy (FTIR) from oxides,
demonstrated the disappearance of characteristic bands by nitrilotriacetates, determining the
complete decomposition of the nitrilotriacetates in oxides / Nos ?ltimos anos, os estudos das propriedades f?sico-qu?micas de ?xidos mistos, tem
despertado o interesse da comunidade cient?fica, propriedades como: piezoeletricidade,
fotoluminesc?ncia, ou aplica??es em cat?lise, surgem destes compostos quando se modifica as
composi??es qu?micas destes materiais, neste contexto algumas rotas s?o empregadas na
s?ntese destes materiais, dentre elas pode-se citar os m?todos: cer?mico, combust?o coprecipita??o,
Pechini ou dos precursores polim?ricos, hidrot?rmico, sol-gel; tais rotas
dividem-se em rotas tradicionais ou em rotas qu?micas. No presente trabalho foram
sintetizados ?xidos com composi??o vari?vel, a partir das decomposi??es t?rmicas dos
nitrilotriacetatos de tit?nio, cobalto, n?quel e praseod?mio. Os nitrilotriacetatos obtidos foram
caracterizados por Espectroscopia de Absor??o na Regi?o do Infravermelho (FTIR),
Termogravimetria (TG/DTG) e Calorimetria Explorat?ria Diferencial (DSC), enquanto que os
?xidos sintetizados foram caracterizados por Difra??o de Raios-X (DRX),
Espectrofluorimetria e Espectroscopia de Absor??o na Regi?o do Infravermelho (FTIR). A
partir dos dados de Espectroscopia de Absor??o na Regi?o de Infravermelho (FTIR),
determinou-se o deslocamento da banda correspondente ao grupo carboxilato (νCOOH) de 1712
cm-1, presente no ?cido nitrilotriac?tico (H3NTA), para a faixa de 1680-1545cm-1, em que
ocorre nos nitrilotriacetatos coordenados. Pelos dados de an?lise t?rmica (TG/DTG/DSC)
indicou-se que em atmosfera oxidante (ar) os ?xidos s?o obtidos a menores temperaturas do
que em atmosfera inerte N2(g). Por Difra??o de Raios-X (DRX), determinou-se que os ?xidos
obtidos s?o cristalinos, e que as fases predominantes obtidas nos titanatos sintetizados, s?o as
fases rutilo e ilmenita. Por Espectrofluorimetria observou-se que a intensidade das bandas de
emiss?o s?o diretamente proporcionais ? concentra??o dos ?ons Ni2+, Co2+ e Pr3+. A partir dos
dados fornecidos pela Espectroscopia de Absor??o na Regi?o do Infravermelho (FTIR) dos
?xidos, demonstrou-se a remo??o das bandas caracter?sticas dos estiramentos dos
nitrilotriacetatos, ap?s tratamento t?rmico, indicando a completa decomposi??o dos
nitrilotriacetatos em ?xidos
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17690 |
| Date | 28 February 2013 |
| Creators | Fonseca, Saulo Gregory Carneiro |
| Contributors | CPF:16225422404, http://lattes.cnpq.br/3511004608337461, Lemos, Francisco das Chagas Dantas de, CPF:19907028487, http://lattes.cnpq.br/8124102870104095, Oliveira, Jo?o Bosco Lucena de, CPF:19127537404, http://lattes.cnpq.br/1360004695124740, Moura, Maria de F?tima Vit?ria de, CPF:31482015404, http://lattes.cnpq.br/2959800336802498, Silva, Ademir Oliveira da |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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