Análise por espectroscopia de fotoluminescência de nanotubos de carbono em filmes de sílica e em solução de NaDDBS

• Ano de defesa: 2010
• Autor(a) principal: Filype Soares Machado
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Nanotubo de carbono; Espectroscopia de Espalhamento Raman; Fotoluminescência; Espectroscopia de espalhamento Raman; Física
• Link de acesso: http://hdl.handle.net/1843/IACO-86GS2X

This dissertation presents and discusses results of studies of Photoluminescence Spectroscopy (PL) and Raman spectroscopy in samples with Single Wall Carbon Nanotubes (SWNT) in silicamatrix. We also look at maps of Photoluminescence Photoexcitation Spectroscopy (PLE) in samples of SWNT in aqueous suspension. With Raman spectroscopy we identified the presence of SWNT's in the samples with nanotubes in silica matrix and, once identified the presence of the tubes, we try to obtain the photoluminescence spectrum of SWNT in this new material for future studies involving the identification and analysis of isolated semiconductor SWNT's. The results showed a very efficient incorporation of nanotubes in 2 samples but no sign ofphotoluminescence. We discuss the absence of PL in the samples and suggest alternative ways of preparing samples to generate luminescent ones. In addition to the experiments in SWNT in glass matrix we measured samples of nanotubes dispersed in NaDDBS solutions in order to demonstrate the technique of photoluminescence excitation and thus suggest a possible distribution of nanotubes in the solution, determining the species through the indexes (n, m) that determine its chiral vector. In this case the main objective was to compare the effect of treatment time in ultrasound, used to disperse the nanotubes, between two samples. One was prepared with high exposure to ultrasound, as is usually done, and one with low time sonification. The results showed that the short time of sonification generates sample with low content of tubes and isolated nanotubes mainly in small clusters.