Desenvolvimento de transdutores baseados em paládio-porfirinas para a detecção de O2 através dos tempos de vida de fosforescência

• Ano de defesa: 2013
• Autor(a) principal: Moraes Filho, Alexandre Francisco de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Tecnológica Federal do Paraná; Curitiba; Programa de Pós-Graduação em Engenharia Elétrica e Informática Industrial
• Palavras-chave em Português: Transdutores; Detectores ópticos; Fotoluminescência; Oxigênio; Instrumentos e aparelhos médicos; Transducers; Optical detectors; Photoluminescencia; Oxygen; Medical instruments and apparatus
• Link de acesso: http://repositorio.utfpr.edu.br/jspui/handle/1/512

This research presents the development of sensing membranes for detection of gaseous oxygen by time-resolved phosphorescence as well as the description of a measurement system for performance evaluation of those elements. The transducers are formed by the immobilisation of palladium metalloporphyrins probes (coproporphyrin I, mesoporphyrin IX, deuteroporphyrin IX and meso-Tetrapenta(fluorophenyl) porphyrin) in polymers of poly(vinyl chloride) and polystyrene. A light emitting diode is employed for dye excitation and the phosphorescence is detected by a miniature photomultiplier tube. The production of the membranes as well as their practical parameters such as calibration curves, ageing, response times and light stability are reported. PVC membranes exhibited moderate sensitivity, with ratios τ0/τair near 4, enabling measurements with a resolution of 10 μs.%-1 for the range of 16% of O2 up to 20,5%. For PS membranes, the ratios τ0/τair reached up to 50, with resolutions of up to 900 μs.%-1 considering concentrations between 0% and 1% of O2, however they proved to be of difficult application for concentrations above 16%. Some sensor membranes showed response times below 1 s. Thus, possible applications for these devices include monitoring of human respiration and detection of residual oxygen (e.g.: food packaging). Also, it was observed a high signal degradation when the dyes are excited around their B bands. PdTFPP dye presented more light stability than the others.