Banca de DEFESA: MICHELLE DE PAULA MADEIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE: MICHELLE DE PAULA MADEIRA
DATA: 07/07/2023
HORA: 08:30
LOCAL: auditório ppgcm
TÍTULO: A study of powder and supported application of titanate nanotubes
PALAVRAS-CHAVES: Titanate nanotubes. Electrophoretic deposition. Ion exchange. Wettability. Antibacterial.
PÁGINAS: 90
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

 Nanomaterials are fundamental to nanoscience and nanotechnology. Among the various nanomaterials, titanate nanotubes have been used in several applications due to their large surface area, layered structure, and ion exchange capacity. In this work we present the results of a research that aimed to investigate the application of titanate nanotubes in powder and/or supported. Initially, a review was carried out on materials and techniques to obtain selfcleaning and/or antimicrobial surfaces. This was done to outline the application given to nanotubes in our study. The results showed titanium dioxide as the most frequently used material to obtain surfaces with these properties, spin-coating and dip-coating as the main deposition techniques and Staphylococcus aureus and Escherichia coli were the bacteria most used in antibacterial assays. In the second stage of the doctoral research, sodium titanate nanotubes were deposited on FTO glass via electrophoretic deposition. The surfaces obtained showed high wettability and inhibited the adhesion of E. coli. In addition, a reduction in the adhesion of S. aureus was observed in relation to the control surface. Direct contact assay with powder nanotubes and under UV-visible light showed an increase in the inhibition rate (of ƞ = 4.1% for ƞ = 25.4%) of E. coli due to the action of reactive oxygen species. In the third stage of the research, the application of sodium titanate nanotubes after ion exchange with cerium and/or gallium ions was performed. The specific surface area of the nanotubes increased considerably after ion exchange. Furthermore, after direct contact assay under visible light, there was an increase in bacterial inhibition of S. aureus, especially for the sample exchanged with cerium and gallium (ƞ = 83.1%). E. coli had similar inhibition (ƞ ~56%) for cerium and cerium/gallium exchanged nanotubes. Thus, titanate nanotubes have potential for antibacterial application either in powder form or deposited on a substrate.

MEMBROS DA BANCA:
Presidente - 1722880 - JOSY ANTEVELI OSAJIMA FURTINI
Interno - 1113300 - FERNANDA ROBERTA MARCIANO
Externo ao Programa - 1714296 - MARIA LETICIA VEGA
Externo à Instituição - JORGE DAVID ALGUIAR BELLIDO - UFSJ
Externo à Instituição - JUAN ANTONIO CECILIA - US