Aplicações de técnicas de imageamento no estudo de (nano)compósitos naturais e sintéticos

• Ano de defesa: 2020
• Autor(a) principal: Oliveira, Naiara Cipriano
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Técnicas de imageamento; Terra mulata de índio; Borracha natural do látex
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/59956

In the present thesis, it is described three scientific articles on the application of advanced imaging techniques, by optical and electron microscopy, used for the study of Brazilian samples Terra Mulata de Índio (TMI) and natural rubber latex; as well as the analysis of the data obtained through image processing. The first work presented here, entitled “Morphological analysis of soil particles at multiple length-scale reveals nutrient stocks of Amazonian Anthrosols”, investigated ex-situ (without any previous chemical processing of the samples) particles in three different types of Brazilian soils (oxisol, ultisol, and Amazonian anthrosol “TMI”) at multiple length-scale using large-field scanning electron microscopy. In this study, the particle size distributions of the particles found in soil samples were calculated with unmatched precision due to computational analyses. In anthrosols were found carbon particles whose chemical structure was unveiled by confocal Raman microspectroscopy. Besides, through the analytical approach used, it was also possible to present a “fingerprint” of the morphology and structure of the particles of TMI, soil with high and sustained fertility. The second scientific article, entitled “Towards the production of natural rubber-calcium phosphate hybrid for applications as bioactive coatings”, describes the analysis of the morphological, structural, and physicochemical stability of natural rubber coatings incorporated with bioactive calcium phosphate microparticles through the application of imaging techniques. The encapsulation capacity of the natural polymer was also evaluated, as well as its stability as a coating in a biologically relevant medium for future bio-related applications. Finally, the third study, entitled “In situ study of the mechanical-chemical stability of natural rubber films using fluorescent silica nanoparticles as probes”, reported how it is possible to evaluate in situ by using imaging techniques the morphological and structural characteristics of natural rubber composite films incorporated with fluorescent silica core-shell nanoparticles, without any modification in the samples. Besides, this study also investigated the stability of films under flow conditions in a medium of high ionic strength (NaCl 0.85%) monitored by laser scanning confocal microscopy. In this sense, the thesis in question contributes significantly to the construction of the scientific and technological knowledge regarding the application of imaging techniques in the investigation of relevant biological samples to the world scenario, and the approaches presented here can be extended to other areas of the knowledge.