Banca de DEFESA: CAMILA CARVALHO DE OLIVEIRA SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : CAMILA CARVALHO DE OLIVEIRA SANTOS
DATE: 19/09/2022
TIME: 08:00
LOCAL: Instituto de Química
TITLE:

NINA synthesis: a new strategy for large-scale production of gold nanorods using the silver-assisted seed-mediated method

KEY WORDS:

gold nanorods, synthesis, metallic nanoparticles, spectroscopic characterization

PAGES: 163
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Química de Interfaces
SUMMARY:

The present work aims to obtain quality and uniform gold nanorods (AuNBs) from the same synthesis, so that amount of material is sufficient to advance in several stages of application research, which is still a current challenge. The importance of AuNBs is significant due to their optical, catalytic, photothermal, SERS and other properties. In order to provide a solution to this question, in the present thesis, a strategy for the production of gold nanorods via large-scale silver-assisted seed-mediated synthesis was considered, as well as the characterization of the surface of Au-NBs via XPS to contribute to the understanding of the role of chemical species on the surface of these nanoparticles. The large-scale synthesis, named NINA, was carried out in five steps, i-Production of large amount of the growth solution; ii-fractionation of the growth solution into parts and 10ml; iii- seed preparation; iv- introduction of the seed in the portions; v- junction of Au-NBs portions. The material was characterized using the techniques of transmission electron microscopy (TEM), electron spectroscopy in the ultraviolet and visible region (UV-Vis), X-ray photoelectron spectroscopy (XPS). As main results, the production of gold nanorods in quantities of 1 liter stands out. In which the portions that make up the AuNBs solution have greater spectral similarity, UV-Vis, evaluated based on the maximum of the longitudinal peak and width at half height of this peak (fwhm), than the replicas of the original synthesis by Nikoobakht and El Sayed ( 2003), indicating the viability of NINA synthesis. There is a projected production of at least 8 liters from this synthesis method. From the XPS data, a better understanding of the chemical state of the silver species, bromide and CTA+ ions present on the surface of Au-NBs was obtained, highlighting that silver was found in two oxidation states Ag(0) and Ag( I).

BANKING MEMBERS:
Presidente - 1673526 - MARCOS MALTA DOS SANTOS
Interno - 3152029 - MATEUS FERNANDES VENANCIO
Interna - 1100392 - SORAIA TEIXEIRA BRANDAO
Interna - 3156252 - LUIZA AMIM MERCANTE
Interno - 3147385 - GUILHERME AUGUSTO FERREIRA
Externo à Instituição - MADSON DE GODOI PEREIRA - UNEB
Externa à Instituição - CLAUDILENE RIBEIRO CHAVES - UFU
Externo à Instituição - ANTONIO FERREIRA DA SILVA - UFBA