Banca de QUALIFICAÇÃO: ALINE ALENCAR EMERENCIANO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : ALINE ALENCAR EMERENCIANO
DATA : 13/12/2018
HORA: 10:00
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

SYNTHESIS AND CHARACTERIZATION OF Ca3Co4O9 AS A THERMOELECTRIC MATERIAL

PALAVRAS-CHAVES:

Ca3Co4O9; amorphous citrate method; Pechini modified with gelatin; High Energy Ball Milling, electrical properties, Seebeck Coefficient.

PÁGINAS: 60
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

In view of the current scenario in which the demand for cleaner and energy-efficient technologies is growing exponentially and irreversibly, there has been a significant focus on the research and development of thermoelectric materials capable of converting thermal energy (dissipated due to the effect Joule) in electricity. Metal oxides, such as calcium and cobalt oxide, Ca3Co4O9, are a great alternative in terms of such technological interest, since their specific properties added to the improvement of their microstructure allow the production of a stable compound with good thermoelectric characteristics. Among the great challenges to obtain the expected single phase, Ca3Co4O9, we can mention the composition control and the temperature control, since the compound is formed in a very restricted range in the CaO-CoO phase diagram. In order to improve calcium cobalt (C349), three different synthesis techniques followed by thermal treatment (drying at 350 ° C and calcination at 900 ° C) were implanted in this project: the synthesis by the amorphous citrate method without the use of dispersant , the synthesis by the Pechini method modified with gelatin and the synthesis by reaction of solid state with mechanical activation by High Energy Ball Milling - being one of its precursors, CaCO3, coming from shells of shellfish, which reinforces even more the environmental motivation in this search. The different calcium cobalt powders were characterized by X-ray diffraction with refinement using the Rietveld method and the thermal evolution of the precursors as well as the loss of mass was obtained by DTA-TGA. It is also expected to perform the analysis of the microstructure through the scanning electron microscopy and the electrical conductivity and the Seebeck coefficient in order to extract which of the syntheses was more successful.

MEMBROS DA BANCA:
Interno - 1300987 - CARLOS ALBERTO PASKOCIMAS
Externo à Instituição - DANIEL ARAÚJO DE MACEDO - UFPB
Presidente - 1350249 - RUBENS MARIBONDO DO NASCIMENTO