Modelos computacionais para o estudo de compostos sob a influência de nanopartículas e superfícies

• Main Author: Franco Junior, Edison
• Other Authors: Mello, Paula Homem de
• Format: Others
• Language: Portuguese
• Published: 2016
• Subjects: NANOPARTÍCULAS DE PLATINA; ENHANCEMENT; QUENCHING; PROGRAMA DE PÓS-GRADUAÇÃO EM CIÊNCIA E TECNOLOGIA/QUÍMICA - UFABC
• Online Access: http://www.biblioteca.ufabc.edu.brhttp://biblioteca.ufabc.edu.br/index.php?codigo_sophia=102554

Orientadora: Profa. Dra. Paula Homem de Mello === Tese (doutorado) - Universidade Federal do ABC. Programa de Pós-Graduação em Ciência e Tecnologia/Química, 2016. === The interaction between molecules and solids is the subject of study of various areas and has a plethora of technological applications. In this work, we have studied experimentally and computationally two systems: (i) the interaction between fluorophores and platinum nanoparticles and (ii) diclofenac oxidation process using a diamond electrode. From the computational simulation point of view, both systems are challenging because the proposed models have to include minima requirements to explain the behavior observed experimentally. For the first system, it was possible to establish computational and experimental protocols to study the effect of platinum nanoparticles in the absorption and emission spectra of polycyclic aromatic hydrocarbons (PAHs). Absorption and emission spectra of pyrene are suppressed by the nanoparticle presence. On the other hand, anthracene spectra is enhanced. The interaction between nanoparticles and pyrene molecules occurs more rapidly and intensely than with anthracene, what favors the quenching in pyrene spectra, and, in contrast, the enhancement of anthracene bands. For pyrene-nanoparticle system, all transitions are shifted to the metal system, while the anthracene-nanoparticle, there is a charge transfer from nanoparticles towards anthracene during electronic excitation. Regarding the second system, the electrooxidation of diclofenac, there were experimental evidences that the process involves the loss of two electrons and two protons, as well as the formation of dimers. Our study, based on Monte Carlo method and on the density functional theory, was fundamental in establishing important intermediate species in the oxidation process, as well as indicate the relative abundance of dimers obtained.