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Previous issue date: 2016-02-24 / O objetivo do trabalho ? observar o efeito da purifica??o da quitosana (Qt) sobre a forma??o de filmes automontados utilizando complexos inorg?nicos: Na2[Fe(CN)5NO] (NPS) e cis-[Ru(bpy)2ImN(NO)](PF6)3 (RubpyNO), caracteriz?-los pelas t?cnicas de Uv-V?s, Infravermelho e voltametria c?clica. A Quitosana comercial foi purificada em tr?s diferentes formas: neutra, cloridrato e acetato. A caracteriza??o dessas apresentaram diferen?as significativas com rela??o as suas caracter?sticas como umidade, grau de desacetila??o, viscosidade e massa molar. Foi realizado o monitoramento pela t?cnica de Uv-vis do crescimento dos filmes de QtNeutra/NPS; QtAcetato/NPS; QtCloridrato/NPS; QtNeutra/ RubpyNO; QtAcetato/ RubpyNO e QtCloridrato/ RubpyNO. Dentre eles, a quitosana purificada na forma acetato mostrou melhor intera??o com os complexos, formando filmes com melhores ?ndices de correla??o R e deposi??o homog?nea dos materiais a cada bicamada formada. Essa intera??o foi confirmada pela an?lise do espectro do infravermelho dos filmes que apresentou bandas de ambos os compostos. Os estudos eletroqu?micos mostraram que os filmes formados possuem grande estabilidade, melhor resolu??o quando analisados a uma taxa de varredura de 50 mV.s-1 e que as amostras QtNeutra e QtAcetato com NPS apresentam os potenciais de pico melhores definidos sofrendo processos quase revers?veis de degrada??o. Os testes de rea??o de ?cido asc?rbico com os filmes de QtAcetato/NPS e QtAcetato/ RubpyNO mostraram que o primeiro apresentou uma melhor resposta eletroqu?mica. / Chitosan (Qt) has great technological application due to present atoxic features, biodegradable
and renewable. The fact that a cationic polymer makes it capable of forming films by selfassembly
technique, allowing its interaction with various compounds. In this context, this study
aimed to evaluate the influence of purification of Qt in the neutral, acetate and hydrochloride
forms in building self-assembled films by their interaction with nitrosyl complex (SNP and
RubpyNO). Analysis of the degree of deacetylation, viscometry, infrared and thermal analysis
showed that the purified Qt have different characteristics. The formation of the films was
monitored by spectroscopy in the Uv-Vis region and characterized through spectroscopic
techniques infrared (FTIR), thermal analysis (TG/DTG), cyclic voltammetry (CV), scanning
electron microscopy (SEM) and energy dispersive X-ray (EDS). The results showed that Qt
neutral and acetate forming films linear and homogeneous growth, with the interaction of both
materials confirmed by FTIR technique. The results show that cyclic voltammetry of the neutral
and acetate Qt films and the complex behave as semi-reversible processes, except the film
QtAcetato/RubpyNO, which presents itself as an irreversible process. It was observed that chitosan
affects the purification method presented in the redox process for the films due to the shape of
weaker or stronger interaction of the particles according to the load presented by polycations and
polyanions in solution during the formation of automounted film. The images obtained by SEM
and EDS confirmed the presence of layers arranged with uniform coverage and homogeneous
distribution of the elements in the film surface. The TG/DTG analysis confirmed thermal
stability of the films before and after being subjected to VC. Reaction rolls of film with ascorbic
acid (AA) and cysteine showed that the film QtNeutra/RubpyNO showed the best response to both
substances. A straight line equation has been suggested for the determination of AA by
QtNeutra/RubpyNO film and for the determination of cysteine, additional studies are required.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/21605 |
| Date | 24 February 2016 |
| Creators | Nascimento, Luciana Ara?jo |
| Contributors | 03936872449, http://lattes.cnpq.br/7903084274135177, Pontes, Ana Cristina Facundo de Brito, 42396441353, http://lattes.cnpq.br/0435570420479356, Alencar, Ana Ellen Valentim de, 90371950325, http://lattes.cnpq.br/1159936035462341, Pontes, Daniel de Lima, 61954225334, http://lattes.cnpq.br/1903229358912987, Silva, Francisco Ordelei Nascimento da, 79629970368, http://lattes.cnpq.br/7252349929698043, Maciel, Jeanny da Silva, 61924130378, http://lattes.cnpq.br/9484470414986626, Oliveira, Otom Anselmo de |
| Publisher | PROGRAMA DE P?S-GRADUA??O EM QU?MICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| 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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