Made available in DSpace on 2014-12-17T15:41:59Z (GMT). No. of bitstreams: 1
AdrianaPBS_DISSERT.pdf: 2596487 bytes, checksum: f09071ef3141cb36b73492e4246e301b (MD5)
Previous issue date: 2012-03-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The recent interest in obtaining functionalized nanoporous materials for applications
such as heterogeneous catalysts and adsorption of CO2 has increased today. In the latter
application, the introduction of amino groups such as present in the chitosan (CS), in the
nanoporous materials like SBA-15 to generate specific interactions with CO2 has gained
importance. In this work were performed to hydrothermal synthesis of SBA-15 and
subsequent impregnation of the CS in the support mesoporous by the method of the wet
impregnation. The materials were characterized by TG/DTG, DSC, XRD, SEM, FTIR and
adsorption / desorption of N2. The XRD showed that the ordered structure of the support
SBA-15 was preserved after the impregnation and calculations have shown that the average
pore diameter (Dp) and / or the average wall thickness (wt) have been changed due to
introduction of the CS in the samples functionalized. The curves of TG and DSC data
corroborates the XRD, indicating the presence of CS in the nanoporous structure of SBA-15,
as well as micrographs of samples, which allowed the display state of aggregation of the
material obtained. The characteristics of bands absorption in the region of the CS in the FTIR
were identified and interpreted in the samples functionalized, confirming the further
characterization. Measurements showed that the BET surface area decreases in the
functionalized samples, indicating the successive incorporation of the polymer in the
nanoporous support. The activation energy apparent (Ea) for the process of thermal
degradation of CS in the impregnated support was determined by the methods of kinetic
freedom Vyazovkin and Ozawa-Flynn-Wall with the results indicating that the sample
functionalized CS/SBA-15 2,5 % was decrease of the Ea in their degradation of about 10%
compared to 1,0 % CS/SBA-15 sample / O recente interesse em se obter materiais nanoporosos funcionalizados para aplica??es
como catalisadores heterog?neos e na adsor??o de CO2 tem aumentado atualmente. Nesta
?ltima aplica??o, a introdu??o de grupos aminas, como os presentes na quitosana (CS), em
materiais nanoporosos do tipo SBA-15 para gerar intera??es espec?ficas com o CO2 tem
ganhado import?ncia. Assim, neste trabalho foram realizadas a s?ntese hidrot?rmica do SBA-
15 e posterior impregna??o da CS no suporte mesoporoso atrav?s do m?todo de impregna??o
por via ?mida. Os materiais obtidos foram caracterizados por meio de TG/DTG, DSC, DRX,
MEV, FTIR e adsor??o/dessor??o de N2. Os resultados de DRX indicaram que a estrutura
ordenada do suporte SBA-15 foram preservada ap?s a impregna??o e os c?lculos mostraram
que o di?metro m?dio do poro (Dp) e/ou espessura m?dia da parede (wt) foram alterados
devido a introdu??o da CS nas amostras funcionalizadas. As curvas de TG e DSC
corroboraram com os dados de DRX, indicando a presen?a da CS na estrutura mesoporosa do
SBA-15, assim como as micrografias das amostras funcionalizadas, que possibilitou
visualizar o estado de agrega??o do material obtido. As bandas caracter?sticas de absor??o da
CS da regi?o IV foram identificadas e interpretadas nas amostras funcionalizadas,
confirmando as outras caracteriza??es. As medidas de BET mostraram que a ?rea superficial
diminui nas amostras funcionalizadas, indicando a sucessiva incorpora??o do pol?mero no
suporte nanoporoso. A energia de ativa??o aparente (Ea) do processo de degrada??o t?rmica
da CS impregnada no suporte foi determinada por meio dos m?todos de cin?tica livre de
Vyazovkin e de Ozawa-Flynn-Wall com os resultados indicando que a amostra funcionalizada
CS/SBA-15 2,5 % teve uma diminui??o da Ea para a sua degrada??o de aproximadamente de
10% em rela??o a amostra de CS/SBA-15 1,0 %
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17669 |
| Date | 15 March 2012 |
| Creators | Santos, Adriana Paula Batista dos |
| Contributors | CPF:35530502415, http://lattes.cnpq.br/9770622597949866, Guedes, Ana Paula de Melo Alves, CPF:03330987499, http://lattes.cnpq.br/5738717177200782, Coutinho, Ana Carla da Silveira Lomba Sant'ana, CPF:02252659742, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4756411J4, Souza, Luiz Di, CPF:01925100880, http://lattes.cnpq.br/0589648773241934, Ara?jo, Ant?nio Souza de |
| 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 0.0063 seconds