Montmorilonita como suporte para remoção de proteínas no processo de clarificação/estabilização dos vinhos e para obtenção de pigmentos híbridos

• Ano de defesa: 2018
• Autor(a) principal: Trigueiro, Pollyana de Aragão
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Engenharia de Materiais; Programa de Pós-Graduação em Ciência e Engenharia de Materiais; UFPB
• Palavras-chave em Português: Montmorilonita; Adsorção; Proteína; Polifenol; Nanocompósitos; Pigmentos híbridos; Fotoestabilidade; Montmorillonite; Adsorption; Protein; Polyphenol; Nanocomposites; Hybrid pigments; Photo-stability; Argila - Aplicações; Compostos orgânicos; Vinhos; CNPQ::ENGENHARIAS
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/13818

Adsorption of organic molecules in the clays minerals can lead to the formation of the hybrid materials and/or nanocomposites through different interaction mechanisms, making these materials interesting for several applications. The present work presents two different applications for a montmorillonite clay : as a support for the removal of proteins in the process of wine clarification/stabilization and as a support to obtain new pigments, investigating the structural modifications and emphasizing the interactions between the organic compounds and the surface of the inorganic material. In the first study, the nanocomposites based on the adsorption of a model protein and a polyphenol of interest on the surface of the montmorillonite, in a model hydroalcoholic solution, were investigated. The amount of the organic part was determined by ultraviolet-visible (UV-VIS) and thermal (TG/DTG) analysis. X-ray diffraction (XRD) and transmission electronic microscopy (TEM) analyzes reported on the stacking/exfoliation of the layers in the nanocomposites. Nuclear magnetic resonance (NMR) and infrared spectroscopy (ATR-FTIR) methods emphasized the formation of a complex between the protein and the polyphenol before adsorption on the claymineral. The motility/stiffness of the organics was determined by time resolved fluorescence spectroscopy. In the second study, pigments were prepared based on the carminic acid and alizarin organic dyes loaded under montmorillonite pillarized with of Al or Tications, at different pH. The stability of the pigments formed was tested under light for 340 h. The pillarization process was investigated by X-ray diffraction, textural analysis, transmission electronic microscopy and nuclear magnetic resonance in the solid state of 27Al. The interactions between the dyes and the inorganic support were highlighted by infrared spectroscopy, 13C and 27Al solid nuclear magnetic resonance and time resolved fluorescence. The spectra confirmed the complexation between the structure of the dyes and the modified clay, through different adsorption sites. Hybrid pigments based on Al-pillared montmorillonite were more stable under light than the Ti-based hybrids. In oil paint formulations, the pigments were shown to be stable even over a long period of irradiation.