Banca de DEFESA: MICHELINE DAMIAO DIAS MOREIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : MICHELINE DAMIAO DIAS MOREIRA
DATA : 27/04/2017
HORA: 14:30
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

ROUTES OF CHEMICAL SYNTHESES FOR OBTAINING NANOPARTICLES OF Ag/g-Al2O3 and Ag/ZnO WITH BACTERICIDAL PROPERTIES.

PALAVRAS-CHAVES:

nanotechnology alumina, zinc oxide, silver, impregnation, microwave-assisted hydrothermal, sonochemistry, bactericidal activity.

PÁGINAS: 151
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

The progressive demand for water has made the treatment and reuse of effluents a subject of worldwide relevance. Considering this situation, research has been carried out on the use of nanometric materials to obtain nanocomposites with antibacterial properties. In order to improve the obtaining of new materials, several methodologies and preparation techniques have been developed with the aim of controlling the shape and size of particles, which will consequently improve and optimize their properties. This work consists of obtaining, characterization and antibacterial evaluation of nanocomposites obtained by the impregnation of silver (Ag) in commercial alumina (g-Al2O3) and zinc oxide (ZnO) from different synthesis routes: hydrothermal method assisted by micro- Waves, sonoquímico and association of the sonoquímico and hidrotermal, destined to the disinfection of wastewater. A comparative study was performed between the nanoparticles g-Al2O3 and ZnO synthesized by sonochemical and hydrothermal microwave methods, investigating the influence of composition and distribution of particle size on the properties of these nanoparticles.Impregnations of 4%, 8%, 12% and 16% Ag in g-Al2O3 and ZnO were tested. The nanopó was applied in effluent coming from compact ETE (Sewage Treatment Station), after the secondary treatment step, and then, through bacteriological analyzes, the efficiency in the removal of the pathogenic indicators of contamination was evaluated. The results regarding the use of the ZnO nanocomposite impregnated with 8% Ag in the ratio of 0.3g/300 mL for a contact time of 30 minutes, indicated an efficiency of 100.00% in the removal of total coliforms, thermotolerant coliforms and Escherichia coli, reaching standards equal or superior to the already established disinfection techniques. The network parameters of the nanocomposites obtained through XRD, together with the FRX characterization techniques, particle size analysis and the micrographs from the SEM/FEG and EDS confirmed the adequate impregnation of the silver in the oxides. ICP-OES plasma optical emission spectrometry revealed that all samples analyzed had a silver content below the detection limit LD<0.50 mg/L, taking into account the maximum levels established by the current standards, as well as the toxicity to Health and the environment.

MEMBROS DA BANCA:
Externo à Instituição - ANDRE LUIS CALADO ARAUJO - IFRN
Externo à Instituição - CARLA GRACY RIBEIRO MENEZES - UNP
Presidente - 1300987 - CARLOS ALBERTO PASKOCIMAS
Interno - 1802888 - FABIANA VILLELA DA MOTTA
Interno - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE