Banca de DEFESA: RAFAEL CHAVES LIMA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : RAFAEL CHAVES LIMA
DATA : 30/01/2018
HORA: 14:00
LOCAL: Anfiteatro A do CCET
TÍTULO:

ZEOLITE MORDENITE: STUDY ABOUT ITS FORMATION AND CRYSTAL SIZE

PALAVRAS-CHAVES:

zeolite, mordenite, crystallization; crystal size; particle size

PÁGINAS: 190
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Inorgânica
ESPECIALIDADE: Físico Química Inorgânica
RESUMO:

A system for the synthesis of the mordenite zeolite was studied, which made it possible to obtain the MOR phase without indicating the presence of any other phase. Variations in the synthesis parameters were performed aiming the establishment of the relationship between the size and the morphology of the synthesis products with the modifications made. The crystallization temperature showed to be an essential factor in the size of particles and crystallites. Dilution of the synthesis gel provided reduced crystallite aggregation and the variation of the water content in the synthesis implied changes in the zeolitization rates. The sodium content modified the growth of the crystals and the increase of intergrowths and aggregations of particles. Aging did not imply any variation in zeolite formation. The change in the silica source increased the growth rate of the crystals and contributed to changes in the size of the crystals. Larger crystals were obtained from systems with higher concentrations of sodium cations as nanocrystallite aggregates and some nanoparticles were synthesized with the lowering of temperature and the use of silica source with greater specific area. Aggregates of small pure mordenite crystallites of up to about 50 nm were obtained with syntheses performed at 150 ° C, with a lower content of Na + and water ions in the gel, dilution of the already prepared gel and with the use of silica sources of greater specific area (relative to this type of material). Opposite conditions enabled the highest growth, generating crystals up to 1 μm on average. The results showed that it is possible to exert some control over the particle size and crystallites of the mordenite zeolite by adjusting parameters inherent to the conventional synthesis system.

MEMBROS DA BANCA:
Presidente - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Interno - 350509 - ANTONIO SOUZA DE ARAUJO
Externo à Instituição - ADONAY RODRIGUES LOIOLA - UFC