Orientador: Prof. Dr. Wendel Andrade Alves / Tese (doutorado) - Universidade Federal do ABC. Programa de Pós-Graduação em Ciência e Tecnologia/Química, 2016. / Conjugados de moleculas organicas geralmente se arranjam em sistemas complexos multifasicos que sao muito sensiveis ao processamento e ao ambiente quimico local. E alem disso, as interacoes intermoleculares e presenca de moleculas assimetricas introduzem variacoes estruturais no empacotamento molecular e no ordenamento em maiores escalas, o que diretamente afeta as mais diferentes propriedades fisico-quimicas e processos associados ao material estudado. Nesta tese duas abordagens envolvendo a formacao de materiais hibridos baseados em estruturas supramoleculares de polimeros e peptideos foram estudadas. A primeira trata da obtencao de blendas polimericas baseadas em poli-(¿Ã)-caprolactona (PCL) com polianilina (PANI) dopada pelo aminoacido N-Acetil-L-Cisteina (NAC) pelos metodos de solution casting e eletrofiacao. Os materiais foram caracterizados acerca das suas propriedades morfologicas, estruturais e moleculares em diferentes escalas. A partir dos resultados foi obtida a relacao entre a variacao das propriedades da blenda em relacao a diferentes concentracoes de NAC. Os resultados indicam que a NAC aumenta a organizacao e cristalinidade da blenda, alem de mostrar a relacao entre o processamento e a micro-nanoestrutura interna. E mostrado tambem o processo de dopagem da PANI pela acido conjugado da NAC, o qual favorece a formacao de diferentes formas de PANI. Os resultados indicam a formacao de uma estrutura supramolecular mantida por interacoes intermoleculares do tipo enxofre-¿Î (SH-¿Î) entre a PANI e a NAC. O segundo topico e sobre o estudo da formacao de matrizes conjugadas de estruturas supramoleculares de L,L-difenilalanina (FF-MNSs) em duas diferentes estruturas cristalinas, hexagonal P61 e ortorrombica P22121, com microperoxidase-11 (MP11) e o polieletrolito poli(alilamina hidroclorada) (PAH). Com o uso de tecnicas espectroscopicas discute-se o papel da estrutura cristalina na interacao entre as FF-MNSs e a MP11. E por eletroquimica o papel do PAH no sistema e elucidado. Com auxilio de simulacoes computacionais e observada a dopagem do material com estrutura ortorrombica por moleculas de PAH, diminuindo a energia de band-gap em ~1 eV. A cinetica da reacao de catalise de reducao de H2O2 e estudada, e entao e mostrado o processo de deteccao de glicose pela enzima glicose oxidase suportada na matriz hibrida formada. Os resultados presentes nesse trabalho contribuem com o estudo de novos conjugados supramoleculares de peptideos e polimeros. Assim a interacao entre as diferentes moleculas, e os fatores que levam a essas interacoes sao discutidas, trazendo consigo novas consideracoes sobre a formacao de materiais supramoleculares. / Organic molecules conjugates usually arrange itself in complex multiphasic systems that are very sensitive to processing and the local chemical environment. Beyond that, the intermolecular interactions and the presence of asymmetric molecules introduces structural variations in the molecular packing and larger scales order, which directly affects different physical-chemical properties and processes associated with the studied materials. In this thesis, two approaches involving the formation of hybrid materials based on supramolecular structures of polymers and peptides were studied. The first one deals with the obtaining of polymer blends based on poly-(å)-caprolactone (PCL) with polyaniline (PANI) doped by the amino acid N-Acetyl-L-Cysteine (NAC) by the solution casting and electrospinning methods. The materials were characterized by its morphologic, structural and molecular properties in different size scales. From the obtained results, the relation between the changes on the blends properties and different NAC concentration was achieved. The results indicate that NAC enhances the organization and the crystallinity index of the blends, and shows the relation between the obtaining method and the internal micro-nanostructure. Later it is shown that NAC also modify the molecular properties of PANI. Using spectroscopic techniques, the doping process of PANI by the conjugate acid of NAC was studies, showing that NAC favors the formation of different PANI forms. The results indicate the formation of a supramolecular structure maintained by sulfur-ð (SH-ð) interactions between PANI and NAC. The second topic is about the formation of conjugated matrixes of supramolecular structures of L,L-diphenylalanine (FF-MNSs) in two different crystal structures, the hexagonal P61 and the orthorhombic P22121, with microperoxidase-11 (MP11) and the polyelectrolyte poly(allylamine hydrochloride) (PAH). Using spectroscopic techniques, the role of the crystal structure in the interaction between the FF-MNSs and MP11 is discussed. And with electrochemical experiments the role of PAH is elucidated. And using computational simulations it is observed the doping of the orthorhombic structure by PAH molecules, decreasing the band-gap energy in about 1eV. The kinetics of the catalytic reduction reaction of hydrogen peroxide was studies, and is shown as proof of concept the detection of glucose by the enzyme glucose oxidase supported in the obtained hybrid matrix. The presented results in this work contribute with the study of novel supramolecular conjugates of peptides and polymers, and the factors that lead to those interactions are discussed, bringing with it new considerations about the formation of supramolecular materials.
| Identifer | oai:union.ndltd.org:IBICT/oai:BDTD:103643 |
| Date | January 2016 |
| Creators | Kogikoski Junior, Sergio |
| Contributors | Alves, Wendel Andrade |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf, 172 f. : il. |
| Source | reponame:Repositório Institucional da UFABC, instname:Universidade Federal do ABC, instacron:UFABC |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | http://biblioteca.ufabc.edu.br/index.php?codigo_sophia=103643&midiaext=73187, http://biblioteca.ufabc.edu.br/index.php?codigo_sophia=103643&midiaext=73188, Cover: http://biblioteca.ufabc.edu.brphp/capa.php?obra=103643 |
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