MODELAGEM MOLECULAR DE NANOTUBOS DE CARBONO E PORFIRINAS COMO NANOSENSORES DE GASES: UMA ABORDAGEM DE PRIMEIROS PRINCÍPIOS

• Ano de defesa: 2010
• Autor(a) principal: Bevilaqua, Rochele Cristine Aymay
• Orientador(a): Fagan, Solange Binotto
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Franciscana
• Programa de Pós-Graduação: Mestrado Acadêmico em Nanociências
• Departamento: Biociências e Nanomateriais
• País: BR
• Palavras-chave em Português: Nanotubos de Carbono; Óxidos de Ferro; Clorofila a; Feofitina a; Nanosensores; Gases
• Palavras-chave em Inglês: Carbon Nanotubes; Iron Oxides; Chlrophyll a; Pheophytin a; Nanosensors; Gases
• Área do conhecimento CNPq: CNPQ::ENGENHARIAS
• Link de acesso: http://tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/253; http://www.tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/307

In this work, we study nanostructures through first principles calculations based on the Density Functional Theory to use as gas sensors. At first, the proposal is based on the study of carbon nanotubes filled with iron oxides, particularly hematite and magnetite, for interaction with O2, N2 and CO2. Based on the analysis of electronic properties of semiconductors tubes with different diameters SWNT (8,0), (10,0) e (13,0) is verified that gases cause changes in al cases, making them as potential candidates to detect gases on the environment. In addition to these carbon-based nanostructures to serve as nanosensores, a second proposal was raised: the use of biomolecules as gas sensor. We chose the chlorophyll a and pheophytin a (a derivative without a magnesium atom in its structure) as an economically favorable alternative due to its low cost and easy to obtain. In fact, these pigments proved to be good sensor devices because the modest binding energy (-0.20 eV to -0.13 eV chlorophyll a to pheophytin a) that indicate a physical interaction with the gases O2, N2 and CO2. So it s possible to say that we can use both of systems carbon nanotubos filled iron oxides and chlorophyll a and its derivative as filters or gas sensors since the removal of gases from these nanostructures can occur easily making them reusable.