Nanopartículas de ouro em fibras ópticas: uma proposta empírica para detecção de sulfeto de hidrogênio (H2S) por ressonância plasmônica

• Autor(a) principal: Prado, Adilson Ribeiro
• Data de Publicação: 2017
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/9688
• topic: Nanopartículas de ouro; Engenharia Elétrica; Detectores; Fibras ópticas; Nanopartículas; Sulfeto de hidrogênio; 621.3

The interest in detecting H2S arose from need to develop a detection system with advantages over commercial systems, since numerous accidents with fatal victims were registered in different industrial areas. This work developed the design, construction and characterization of an innovative method of detection of hydrogen sulfide, better known H2S, normally found in gas phase at room temperature. H2S is a gas with a high degree of lethality and is commonly found in extraction of petroleum and decomposition of organic material. The detection was performed by combining advantages of silica optical fibers with the potentialities of the gold nanoparticles. The physical principle explored was the localized surface plasmon resonance. The localized surface plasmon resonance is strongly altered when the free electrons of the metal undergo some external perturbation. In the case in question the strong bonding energy between the gold element and sulfur was the main basis for the operation of the developed colorimetric detector. All the stages of detector production have been described in detail: since synthesis of gold nanoparticles by citrate reduction method, to detection process, which was given by fluorescence using a portable fiber-optic spectrophotometer. The process of adhesion of the nanoparticles to fiber followed procedure originally developed in this work, since it was necessary to increase the concentration of the nanoparticles in the circular section of the cleaved tip, being one of the variables linked to the detection limits of H2S. For this, different experiments were carried out to verify behavior of the nanoparticle concentration at the detection of the gas of interest. The operation range of device was between 0.4 to 2.0 ppm, operating at room temperature without the need for conditioning or special routines to start operation.