Made available in DSpace on 2014-12-17T15:41:42Z (GMT). No. of bitstreams: 1
RoseaneSO.pdf: 1884603 bytes, checksum: 9b9e3631718ab941c6e9125f7deb26e8 (MD5)
Previous issue date: 2007-08-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Films of chitosan with trivalent lanthanides ions Eu3+ and Tb3+ were respectively prepared in the ratio of 3:1 m/m (chitosan: lanthanide) and 6:1 m/m (chitosan: lanthanide). There were no formations of films in a ratio of 1:1 m/m
(chitosan: lanthanides). The films of chitosan with the Tb3+ ion have the same transparent appearance than the pure chitosan films. The film of chitosan with Eu3+ ion has a muddy appearance. These films present good resistance to tear. The
appearance of the compounds prepared in ratio 1:1m/m is a white powder. The films and compounds of chitosan were characterized by Elementary Analysis (CHN), Thermal Analysis (TG/DTG) and Spectroscopy of Luminescence. The CHN analysis was made only for compounds prepared in ratio 1:1m/m, suggesting that these compounds possess the formula QUILn.6H2O, where QUI = Chitosan and Ln =
Lanthanide. The results of the curves TG/DTG indicated that there are strong interactions between Eu3+ or Tb3+ and chitosan, causing a lesser lost of mass in the films. The luminescence analysis showed that the films of chitosan with the ions Eu3+ and Tb3+ present emissions in the region of the visible one, with bands of the chitosan and of the Eu3+ ion. The luminescence analysis of the compounds of chitosan with the Eu3+ and Tb3+ ions suggest that the chitosan does not transfer into energy to the ions lanthanides, however the chemical neighborhood around of the ion lanthanides breaks the selection rules and, conseq?ently the 4f-4f transitions of the
lanthanide ions are observed / Filmes de quitosana com os ?ons lantan?deos trivalentes Eu3+ e Tb3+ foram preparados na propor??o de 3:1 m/m (quitosana: lantan?deo) e 6:1 m/m (quitosana:
lantan?deo), respectivamente. Na propor??o 1:1 m/m (quitosana: lantan?deo) n?o houve forma??o de filmes. Os filmes de quitosana com o ?on Tb3+ t?m uma apar?ncia similar ao filme de quitosana pura, mostrando-se transparente. J? o filme de quitosana com o ?on Eu3+ tem uma apar?ncia um pouco turva. Esses filmes apresentaram boa resist?ncia ao rasgo. Os compostos preparados na propor??o 1:1
formaram um s?lido em p? de cor branca. Tanto os filmes como os compostos de quitosana foram caracterizados por An?lise Elementar (CHN), An?lise T?rmica (TG/DTG) e Espectroscopia de Luminesc?ncia. As an?lise de CHN foram feitas apenas para os compostos de quitosana em p?, sugerindo que esses compostos possuem f?rmula geral QUILn.6H2O, onde QUI = Quitosana e Ln = Lantan?deo. Os
resultados das curvas TG/DTG indicam que a introdu??o desses metais na estrutura da quitosana deixa suas liga??es mas fortes, tendo menor perda de massa nos filmes. A an?lise de luminesc?ncia mostrou que os filmes de quitosana com ?on Eu3+ e Tb3+ apresentam emiss?o na regi?o do vis?vel, com bandas referentes ? quitosana e ao ?on Eu3+. Para os compostos de quitosana em p? com os ?ons Eu3+ e Tb3+, a
an?lise de luminesc?ncia sugere que a quitosana n?o est? transferindo energia para o ?on lantan?deo, no entanto a vizinhan?a qu?mica onde se encontra o ?on lantan?deo
quebra as regras de sele??o e favorecem a emiss?o desses ?ons
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17596 |
| Date | 30 August 2007 |
| Creators | Oliveira, Roseane Silva de |
| Contributors | CPF:64145557468, Pereira, M?rcia Rodrigues, CPF:83115951787, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788568T8, Cavalcante, Maria Gorette, CPF:10843329491, http://lattes.cnpq.br/2069510469317474, Alves J?nior, Severino, CPF:81408307472, http://lattes.cnpq.br/9563158536061549, Hussein, Fabiana Roberta Gon?alves e Silva |
| 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 |
Page generated in 0.0024 seconds