Banca de DEFESA: DAMIANA SINÉZIO DE SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : DAMIANA SINÉZIO DE SOUZA
DATE: 06/08/2021
TIME: 14:00
LOCAL: Remotamente pelo google meet
TITLE:

Controlled insertion of aluminum oxide pillars in bentonite clays

KEY WORDS:

Al₁₃; Al₃₀; Keggin, pillarization; clays

PAGES: 115
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Físico Química Inorgânica
SUMMARY:

Clays are minerals widely available in nature. They are applied as catalysts in various chemical processes, such as oil cracking, and chemical transformations in soils. Some specific clays (such as bentonitic) have characteristics that allow us to modify their properties, such as an increase in specific area, an increase in active sites and greater thermal stability. Among the chemical modification processes of clays, there is pillarization, which consists of inserting pillars between the lamellae, increasing the basal spacing and consequently the accessibility of the clay galleries, thus intensifying its adsorptive and catalytic characteristics. A system for the synthesis of pillarization with Al30 was studied, which made it possible to obtain a material with properties superior to those synthesized using traditional methods. Variations were made in the parameters: Application of clay expansion with water, cetyltrimethylammonium bromide (CTMA-OH), tetrapropylammonium bromide (TPA-OH), ethylene glycol (EG), temperature, time, and concentration of reagents. The synthesis temperature of the pillaring solution as well as the heating time together show to be the primary factor in relation to the size of the basal spacings. The concentration of reagents also contributed to obtain Al30. The best results were obtained for the pillaring solution with ratio [OH]/[Al] = 2.4, temperature of 95°C for 12h. The results showed that it is possible to obtain some control over the insertion and size of columns in pillars with bentonite clays by adjusting the parameters of the synthesis system commonly used for pillars with Al13.

BANKING MEMBERS:
Externo à Instituição - FABIO GARCIA PENHA - IFRN
Externo ao Programa - 1804952 - FERNANDO JOSÉ VOLPI EUSÉBIO DE OLIVEIRA
Externa à Instituição - LINDIANE BIESEKI - UFRN
Externo à Instituição - Manuel Karim Sapag - UNSL
Presidente - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Interno - 2087667 - TIAGO PINHEIRO BRAGA