Banca de DEFESA: ANA LETICIA FERNANDES DOS SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANA LETICIA FERNANDES DOS SANTOS
DATE: 31/01/2025
TIME: 14:30
LOCAL: meet.google.com/ysi-irdz-hxk
TITLE:

Investigation of different organosilanes on the functionalization and dispersion degree of reduced graphene oxide (rGO) in polymeric nanocomposites

KEY WORDS:

GRAPHENE; FUNCTIONALIZATION; ORGANOSILANE; POLYMERIC NANOCOMPOSITE; DISPERSION.

PAGES: 66
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Polímeros, Aplicações
SUMMARY:

Graphene is gaining more and more attention due to its unique properties, and is increasingly being applied in various sectors, including its application as a nanofiller in polymeric matrices. However, this nanomaterial finds challenges in this application due to factors that contribute to low dispersion in the matrix and, consequently, lower than desired properties. Thus, chemical modification of its surface can be a key alternative for expanding it into different applications. This work aims to evaluate the degree of dispersion of reduced graphene oxide (rGO) functionalized with different organosilanes in an epoxy polymer matrix. To this end, graphene oxide (GO) was first synthesized in the laboratory, functionalized with 3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane (APTMS), 3-glycidoxypropyltrimethoxysilane (GPTMS) and triethoxymethylsilane (MTES), and then thermally reduced to produce functionalized reduced graphene oxides. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscopy, thermogravimetry (TGA), solvent dispersion stability and scanning electron microscopy (SEM) analyses were carried out to analyze the functionalization efficiency, as well as to prove the successful synthesis of these materials. The results obtained confirmed the success of covalent functionalization with all the silanes used on the surface of GO, as well as the permanence of their molecules in the basal plane of carbons of reduced graphene oxide (rGO). To check the degree of dispersion in the polymer matrix, polymer nanocomposites were prepared with 0.5% by mass of each functionalized rGO. Analysis of the fracture surfaces of these materials by SEM showed that better distribution, dispersion and interfacial bonding were obtained for nanocomposites containing functionalized rGO rather than pure rGO. It was possible to observe that the dispersion of the nanoparticles improved for the nanocomposites containing rGO functionalized with the different organosilanes, and the most satisfactory results were obtained for the nanocomposites containing rGO/APTES.

COMMITTEE MEMBERS:
Presidente - 1755267 - MARIA CAROLINA BURGOS COSTA DO NASCIMENTO
Interno - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE
Externa à Instituição - AMELIA SEVERINO FERREIRA E SANTOS - UFPB