Caracterização termo-óptica de resinas dopadas com nanocristais semicondutores: efeitos de incidência de radiação ionizante

• Ano de defesa: 2019
• Autor(a) principal: Oliveira Júnior, Marcos Garcia de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Uberlândia; Brasil; Programa de Pós-graduação em Física
• Palavras-chave em Português: Física; Resinas; Dosímetros; Pontos quânticos; CNPQ::CIENCIAS EXATAS E DA TERRA
• Link de acesso: https://repositorio.ufu.br/handle/123456789/28775; http://dx.doi.org/10.14393/ufu.di.2019.38

In this work,the polyester resins doped with semiconductornanostructures (or quantum dotsQDs) of CdSe /ZnS were prepared. The resins were obtained with three different sizes of QDs (5.1, 2.9 or2.4 nm), and different concentrations. From these materials, two sets ofresins were made, and the first set wasmade only for the QDsof 5.1 nm and withvariable concentrations;the second set of samples was performed with quantum dots of different sizesand for the same concentration. The emission spectra of all the samples were performed at 409 nm, and their respective thermo-opticalparameters were determined. Themode-mismatched ThermalLens (TL) technique was used to obtain the thermo-optical parameters (thermal diffusivityand the parameter proportional to the TL amplitude normalized by the absorbed power θ /Pabs) using an excitation beam at514.5 nm. Spectroscopic and thermo-optical characterizations were performed before and after the resins were irradiated with X-rays using a linear high-voltage accelerator with 5 different dosages (2,4,6,8 and 10 Gy). The optical properties of the resins doped with CdSe/ZnS QDs were compared before and after X-ray irradiation, in orderto determine the potential of the QDs to detect the presence of X-rays, aiming at a possible dosimeter application.