Banca de DEFESA: ANDREZA BERNARDES DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANDREZA BERNARDES DA SILVA
DATE: 20/07/2023
TIME: 10:00
LOCAL: Remoto - virtual - google meet
TITLE:

TiO₂ QUANTUM DOTS: AN INNOVATIVE NANOMATERIAL FOR TEXTILE MATERIALS FUNCTIONALIZATION

KEY WORDS:

TiO₂ Quantum Points, Gold Nanoparticle, technological innovation, Photocatalysis, Textile Fibers.

PAGES: 110
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Tecnologia Química
SPECIALTY: Têxteis
SUMMARY:

The UN's 2030 agenda aims to achieve this sustainability through 17 objectives, namely: industry, innovation and infrastructure; clean water and sanitation. In this sense, it is necessary to search for sustainable materials, in particular, to act in the treatment of water in the textile industry, which is one of the largest consumers of water in its chemical processes and with a low reuse rate and, consequently, generating a high load. of polluting effluents. Thus, nanomaterials are widely studied and used for applications that minimize this problem. One of the applications is via photocatalysis processes, due to the high efficiency of these nanostructures due to their surface area, such as: TiO₂, ZnO and other semiconductors. Other emerging nanomaterials are nanoparticles with reduced size in the range of 1-10 nanometers, which, due to their size, undergo quantum confinement and are therefore called quantum dots. The main problem involving TiO₂ quantum dots is the agglomeration of particles in the medium, which makes their use in photocatalysis complex, since a secondary treatment is necessary to recover it. In this proposed study, the objective was to evaluate the applicability of TiO2 quantum dots (TiO₂ PQs) immobilized in textile fibers for potential photocatalytic application. The synthesis of PQs TiO₂ was performed via solgel and in the first stage of this study, immobilized on soybean fibers by the layer-by-layer method using chitosan as a cationizing agent. The photocatalytic evaluation was carried out using a concentration variation (2 to 8 ppm) of rhodamine B. In the second study, a Box-Behken-type factorial design was used where the variables: TiO₂/Au ratio (%), temperature, time and pH of the immobilization solution, having as response variable, the photodegradation of the reactive dye black 5 (C26H25N5O19S6), one of the most used dyes in the textile industry. Soybean and polyamide fabric samples were characterized for their microstructural properties using XRD, XPS, HRTEM-SAED, SEM-FEG as well as colorimetric analyses. The results prove that the obtained quantum dots present a tetragonal crystalline structure, corresponding to the anatase phase, with a size approaching 6 nm. The results of the photocatalysis of the functionalized soy fiber showed excellent photocatalytic efficiency, degrading 2 ppm of Rhb in 120 minutes, with durability of up to 5 cycles of reuse, with a loss of approximately 10% of its photocatalytic efficiency. The polyamide fabric nanocoated with PQs TiO₂/Au, presented an efficiency of approximately 100% of photodegradation of 20 ppm of the RB5 dye, in 240 minutes and with reuse stability in 5 consecutive cycles. Therefore, the application of quantum dots in textile fibers as functionalization agents is a promising way to obtain flexible surfaces with excellent photocatalytic properties.

COMMITTEE MEMBERS:
Interna - 2254759 - AMANDA MELISSA DAMIAO LEITE
Externa à Instituição - CARLA MANUELA PEREIRA MARINHO DA SILVA - UMinho
Interno - 2941160 - JOSE HERIBERTO OLIVEIRA DO NASCIMENTO
Externo à Instituição - NIVALDO FREIRE DE ANDRADE NETO - UFRN
Externo à Instituição - PIERRE BASILIO ALMEIDA FECHINE - UFC