Estudo das propriedades estruturais e fotofísicas de blendas poliméricas base grupos metacrilato/fluoreno

• Ano de defesa: 2013
• Autor(a) principal: Menezes, Durval Bertoldo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Uberlândia; BR; Programa de Pós-graduação em Física; Ciências Exatas e da Terra; UFU
• Palavras-chave em Português: Blendas poliméricas; Elipsometria de emissão; Sonda luminescente; Temperaturas de relaxações α β γ e δ; Polímeros conjugados; Luminescência; Polymer blends; Emission ellipsometry; Luminescent probe; Temperatures Relaxations α β γ and δ; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://repositorio.ufu.br/handle/123456789/15655; https://doi.org/10.14393/ufu.di.2013.195

In this work were studied optical properties of polymeric blends of luminescent conjugated polymer poly (9,9 n-dihexyl-2,7-fluorenodiilvinileno-alt-1,4-henylenevinylene) (LAPPS16) in atactic polymeric matrix: poly (methyl methacrylate) (PMMA) (75,000 MW), poly (ethyl methacrylate) (PEMA) (MW 350,000) and poly(isopropyl methacrylate) (PiPMA) (MW 100,000) were studied. The blends are self-standing films were made by co-precipitation process and these properties were then investigated by optical absorbance, photoluminescence (PL), photoluminescence of excitation(PLE), emission ellipsometry (EE) and photoluminescence in situ temperature. The samples were structurally characterized by x-ray diffraction and measurements showed that does not structural changes in the matrices of methacrylates. The optical absorbance and emission ellipsometry showed that the luminescent polymer LAPPS16 is highly diluted with low aggregates on the samples studied. The states of polarized emitted light by films were studied by emission ellipsometry technique. The samples were excited by linear vertically polarized light and the measured emission is more polarized when conjugated segments smaller gap of energy, i.e. higher length of conjugated. This result is related to the process of transfer energy inter and intramolecular. The relaxation temperature of atactic polymers PMMA, PEMA and PIPMA were verified by variation of photoluminescence intensity and wavelength of excitation, which was performed on the temperature range from 35K to 410K. This study showed that luminescent polymeric probe, LAPPS 16, suffer influence of relaxation temperatures α, β, γ and δ of methacrylate, meanly when there is an energy transfer on LAPPS16 excited with high energy. Finally, this worked showed the luminescent polymer, how LAPPS16, could be used for study dynamics properties in system matrix guest-host.