Espectroscopia Raman por elipsometria aplicada a moléculas orgânicas
In this work we show the potencial of the ellipsometric Raman spectroscopy technique (ERS) in obtaining additional information about the structures of various organic materials, complementary to other optical spectroscopy techniques, through the study of polarization of the scattered light. The ERS...
| Autor: | |
|---|---|
| Tipo de documento: | Tesis doctoral |
| Estado: | Published version |
| Fecha de publicación: | 2020 |
| País: | Brasil |
| Institución: | UFU |
| Repositorio: | Repositório Institucional da UFU |
| Lenguaje: | Portugués |
| OAI Identifier: | oai:repositorio.ufu.br:123456789/31260 |
| Acceso en línea: | https://repositorio.ufu.br/handle/123456789/31260 http://doi.org/10.14393/ufu.te.2020.307 |
| Nivel de acceso: | Acceso abierto |
| Palabra clave: | Fotofísica Proteínas PMMA BSA ERS Photophysics Polymers Proteins CNPQ::CIENCIAS EXATAS E DA TERRA Física Polímeros |
| _version_ | 1878751550669586432 |
|---|---|
| author | Basílio, Fernando Costa |
| author_browse | Basílio, Fernando Costa |
| author_facet | Basílio, Fernando Costa |
| author_role | author |
| collection | Repositório Institucional da UFU |
| description | In this work we show the potencial of the ellipsometric Raman spectroscopy technique (ERS) in obtaining additional information about the structures of various organic materials, complementary to other optical spectroscopy techniques, through the study of polarization of the scattered light. The ERS technique was developed in the material spectroscopy group and presented for the first time to the scientific community in an article by me and collaborators entitled "ellipsometric Raman spectroscopy" published in 2016. The ERS relates the polarization of scattered light by calculating Stokes parameters, with the structure of molecules. Through the Stokes parameters, several physical parametersare calculated, for example, degree of polarization (P) and asymmetry factor (g), the latter can be related to the Raman optical activity signal (ROA - short for Raman optical activity) which is used to characterize secondary protein structures. In the poly (methyl methacrylate) (PMMA), the polymer-solvent interaction in chloroform, tetrahydrofuran (THF) and toluene was analyzed. The ERS demonstrated that the solvents chloroform and THF interact with the polymeric matrix in an anisotropic manner, mainly with the methyl branch and toluene in an isotropic manner in the analyzed regions. In addition, she was able to identify the temperature relaxations and of the PMMA. In bovine serum albumin (BSA - short for bovine serum albumin), its structural conformation in changing the chemical environment from pH 2 to 12 was studied. In order to analyze this change, optical absorption, circular dichroism, photoluminescense, Raman scattering measurements were performed and tia total agreement of these resulta with the literature was verified. Through the ERS technique, as it is a technique capable of observing localized changes, it was observed that the aromatic amino acids rotate in relation to the main chain in a way that at more acidic pH they are unmasked from within the BSA structure and for more basic means they get more embedded in the protein. This is just one of the additional information removed by the ERS, in the text other surprising information will be addressed. The chiral conjugated polymer (1R, 2R) diaminocyclohexane, which is a new material in the literature and was studied in its polymeric form (named in this work by SW254) and in the form of oligomer (named in this job by SW203). For the optical characterization the most varied spectroscopic technique were used, among them, the circular excitation dichroism and the ERS. Among several relevant results, we highlight the ability to control the polarization of light through the excitation length and the asymmetry caused by exciton coupling between the benzene and stylbenzene groups. Dias e tão characteristics make (1R, 2R) diaminocyclohexane a promising material and can be used for the manufacture of metamaterials. |
| eu_rights_str_mv | openAccess |
| format | doctoralThesis |
| id | BR_1c8a2fc0daa5203beac2e5dae271dd2d |
| institution | UFU |
| instname_str | Universidade Federal de Uberlândia (UFU) |
| language | por |
| network_acronym_str | BR |
| network_name_str | Brasil |
| oai_identifier_str | oai:repositorio.ufu.br:123456789/31260 |
| publishDate | 2020 |
| publishDateSort | 2020 |
| publisher | Universidade Federal de Uberlândia Brasil Programa de Pós-graduação em Física |
| publisherStr | Brasil Programa de Pós-graduação em Física Universidade Federal de Uberlândia |
| reponame_str | Repositório Institucional da UFU |
| spelling | Espectroscopia Raman por elipsometria aplicada a moléculas orgânicas Ellipsometric Raman spectroscopy applied to organic molecules Basílio, Fernando Costa Fotofísica Proteínas PMMA BSA ERS Photophysics Polymers Proteins CNPQ::CIENCIAS EXATAS E DA TERRA Física Polímeros In this work we show the potencial of the ellipsometric Raman spectroscopy technique (ERS) in obtaining additional information about the structures of various organic materials, complementary to other optical spectroscopy techniques, through the study of polarization of the scattered light. The ERS technique was developed in the material spectroscopy group and presented for the first time to the scientific community in an article by me and collaborators entitled "ellipsometric Raman spectroscopy" published in 2016. The ERS relates the polarization of scattered light by calculating Stokes parameters, with the structure of molecules. Through the Stokes parameters, several physical parametersare calculated, for example, degree of polarization (P) and asymmetry factor (g), the latter can be related to the Raman optical activity signal (ROA - short for Raman optical activity) which is used to characterize secondary protein structures. In the poly (methyl methacrylate) (PMMA), the polymer-solvent interaction in chloroform, tetrahydrofuran (THF) and toluene was analyzed. The ERS demonstrated that the solvents chloroform and THF interact with the polymeric matrix in an anisotropic manner, mainly with the methyl branch and toluene in an isotropic manner in the analyzed regions. In addition, she was able to identify the temperature relaxations and of the PMMA. In bovine serum albumin (BSA - short for bovine serum albumin), its structural conformation in changing the chemical environment from pH 2 to 12 was studied. In order to analyze this change, optical absorption, circular dichroism, photoluminescense, Raman scattering measurements were performed and tia total agreement of these resulta with the literature was verified. Through the ERS technique, as it is a technique capable of observing localized changes, it was observed that the aromatic amino acids rotate in relation to the main chain in a way that at more acidic pH they are unmasked from within the BSA structure and for more basic means they get more embedded in the protein. This is just one of the additional information removed by the ERS, in the text other surprising information will be addressed. The chiral conjugated polymer (1R, 2R) diaminocyclohexane, which is a new material in the literature and was studied in its polymeric form (named in this work by SW254) and in the form of oligomer (named in this job by SW203). For the optical characterization the most varied spectroscopic technique were used, among them, the circular excitation dichroism and the ERS. Among several relevant results, we highlight the ability to control the polarization of light through the excitation length and the asymmetry caused by exciton coupling between the benzene and stylbenzene groups. Dias e tão characteristics make (1R, 2R) diaminocyclohexane a promising material and can be used for the manufacture of metamaterials. CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico FAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas Gerais FAPESP - Fundação de Amparo a Pesquisa do Estado de São Paulo Tese (Doutorado) Neste trabalho mostramos o potencial da técnica espectroscopia Raman por elipsometria (ERS - abreviação do inglês ellipsometric Raman spectroscopy) em obter informações adicionais sobre as estruturas de diversos materiais orgânicos, complementares à outras técnicas de espectroscopia óptica, através do estudo da polarização da luz espalhada. A técnica ERS foi desenvolvida no grupo de espectroscopia de materiais e apresentada pela primeira vez para a comunidade cientifica no artigo de minha autoria e colaboradores intitulado “Ellipsometric Raman Spectroscopy” publicado em 2016. O ERS relaciona a polarização da luz espalhada, através do cálculo dos parâmetros de Stokes, com a estrutura das moléculas. Através dos parâmetros de Stokes calcula-se diversos parâmetros físicos, por exemplo, grau de polarização () e fator de assimetria (), este último pode ser relacionado ao sinal de atividade óptica Raman (ROA – abreviação do inglês Raman optical activity) que é utilizado para caracterizar estruturas secundárias de proteínas. No poli (metil metacrilato) (PMMA) foi analisado a interação polímero-solvente em clorofórmio, tetrahidrofurano (THF) e tolueno. O ERS demonstrou que os solventes clorofórmio e THF interagem com a matriz polimérica de forma anisotrópica, principalmente com o ramo metil e o tolueno de forma isotrópica nas regiões analisadas. Além disso, ela foi capaz de identificar as temperaturas relaxações térmicas e do PMMA. Na albumina do soro bovino (BSA – abreviação do inglês bovine serum albumin) foi estudada sua conformação estrutural na mudança de ambiente químico de pH 2 a 12. Para analisar esta mudança foram realizadas medidas de absorção óptica, dicroísmo circular, fotoluminescência, espalhamento Raman e verificou-se a total concordância destes resultados com a literatura. Através da técnica ERS, por ser uma técnica capaz de observar mudanças localizadas, foi observada de que os aminoácidos aromáticos rotacionam em relação a cadeia principal de uma forma que em pH mais ácidos eles se desmascaram de dentro da estrutura da BSA e para meios mais básicos eles se incrustam mais na proteína. Essa é somente uma das informações adicionais retiradas pelo ERS, no texto será abordado outras informações muito relevantes. O polímero conjugado quiral (1R, 2R) diaminociclohexano, que é um material novo na literatura e foi estudado na sua forma polimérica (nomeada neste trabalho de SW254) e na forma de oligômero (nomeada neste trabalho de SW203). Para a caracterização óptica utilizouse as mais variadas técnicas espectroscópicas, entre elas, o dicroísmo circular de excitação e o ERS. Dentre vários resultados relevantes, destacam-se a capacidade de controlar a polarização da luz através do comprimento de excitação e a assimetria causada pelo acoplamento éxciton entre os grupos benzenos e estilbenzenos. Essas duas características fazem do (1R, 2R) diaminociclohexano um material promissor, podendo ser utilizado para a fabricação de metamateriais. Universidade Federal de Uberlândia Brasil Programa de Pós-graduação em Física BASILIO, Fernando Costa. Espectroscopia Raman por elipsometria aplicada a moléculas orgânicas. 2020. 210 f. Tese (Doutorado em Física) - Universidade Federal de Uberlândia, Uberlândia, 2020. DOI http://doi.org/10.14393/ufu.te.2020.307. https://repositorio.ufu.br/handle/123456789/31260 http://doi.org/10.14393/ufu.te.2020.307 |
| spellingShingle | Espectroscopia Raman por elipsometria aplicada a moléculas orgânicas Basílio, Fernando Costa Fotofísica Proteínas PMMA BSA ERS Photophysics Polymers Proteins CNPQ::CIENCIAS EXATAS E DA TERRA Física Polímeros |
| status_str | publishedVersion |
| title | Espectroscopia Raman por elipsometria aplicada a moléculas orgânicas |
| title_full | Espectroscopia Raman por elipsometria aplicada a moléculas orgânicas |
| title_fullStr | Espectroscopia Raman por elipsometria aplicada a moléculas orgânicas |
| title_full_unstemmed | Espectroscopia Raman por elipsometria aplicada a moléculas orgânicas |
| title_short | Espectroscopia Raman por elipsometria aplicada a moléculas orgânicas |
| title_sort | Espectroscopia Raman por elipsometria aplicada a moléculas orgânicas |
| topic | Fotofísica Proteínas PMMA BSA ERS Photophysics Polymers Proteins CNPQ::CIENCIAS EXATAS E DA TERRA Física Polímeros |
| topic_facet | Fotofísica Proteínas PMMA BSA ERS Photophysics Polymers Proteins CNPQ::CIENCIAS EXATAS E DA TERRA Física Polímeros |
| url | https://repositorio.ufu.br/handle/123456789/31260 http://doi.org/10.14393/ufu.te.2020.307 |