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Previous issue date: 2014-01-24 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The Layered Double Hydroxides has become extremely promising materials
due to its range of applications, easily obtained in the laboratory and reusability after
calcination, so the knowledge regarding their properties is of utmost importance. In this
study were synthesized layered double hydroxides of two systems, Mg-Al and Zn-Al,
and such materials were analyzed with X-ray diffraction and, from these data, we
determined the volume density, planar atomic density, size crystallite, lattice
parameters, interplanar spacing and interlayer space available. Such materials were
also subjected to thermogravimetric analysis reasons for heating 5, 10, 20 and 25 ? C /
min to determine kinetic parameters for the formation of metaphases HTD and HTB
based on theoretical models Ozawa, Flynn-Wall Starink and Model Free Kinetics. In
addition, the layered double hydroxides synthesized in this working ratios were
calcined heating 2.5 ? C / min and 20 ? C / min, and tested for adsorption of nitrate
anion in aqueous solution batch system at time intervals 5 min, 15 min, 30 min, 1h, 2h
and 4h. Such calcined materials were also subjected to exposure to the atmosphere
and at intervals of 1 week, 2 weeks and 1 month were analyzed by infrared
spectroscopy to study the kinetics of regeneration determining structural called
"memory effect" / Os Hidr?xidos Duplos Lamelares tem se tornado materiais extremamente
promissores devido a sua gama de aplica??es, f?cil obten??o em laborat?rio e a
possibilidade de reutiliza??o ap?s calcina??o, portanto o conhecimento referente ?
suas propriedades ? de extrema relev?ncia. Neste estudo foram sintetizados
hidr?xidos duplos lamelares de dois sistemas, Mg-Al e Zn-Al, e tais materiais foram
submetidos a an?lise com difra??o de raios X e, a partir de tais dados, foram
determinados a densidade volum?trica, densidade at?mica planar, tamanho do
cristalito, par?metros de rede cristalina, dist?ncia interplanar e espa?o interlamelar
dispon?vel. Tais materiais tamb?m foram submetidos ? an?lise termogravim?trica em
raz?es de aquecimento de 5, 10, 20 e 25 ?C/min para determina??o de par?metros
cin?ticos durante a forma??o das metafases HTD e HTB com base nos modelos
te?ricos de Ozawa, Flynn-Wall, Starink e Model Free Kinetics. Al?m disso, os
hidr?xidos duplos lamelares sintetizados neste trabalhado foram calcinados em raz?es
de aquecimento de 2,5 ?C/min e 20 ?C/min e submetidos a ensaios de adsor??o de
?nion nitrato em solu??o aquosa em sistema de batelada em intervalos de tempo de 5
min, 15 min, 30 min, 1h, 2h e 4h. Tais materiais calcinados tamb?m foram submetidos
? exposi??o com a atmosfera e em intervalos de tempo de 1 semana e 2 semanas
foram analisados atrav?s de difra??o de raios X para estudo determina??o da cin?tica
de regenera??o estrutural denominada efeito mem?ria
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17758 |
| Date | 24 January 2014 |
| Creators | Hora, Paulo Henrique Almeida da |
| Contributors | CPF:16225422404, http://lattes.cnpq.br/3511004608337461, Huitle, Carlos Alberto Martinez, CPF:01139059980, http://lattes.cnpq.br/2485073932883264, Pergher, Sibele Berenice Castella, CPF:50942611004, http://lattes.cnpq.br/5249001430287414, Silva J?nior, Umberto Gomes da, CPF:16233719453, http://lattes.cnpq.br/3952943964796396, Almeida, Francisco Emanoel Ferreira de, CPF:51860210406, http://lattes.cnpq.br/8644741163673055, 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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