Banca de DEFESA: BÁRBARA SCHNEIDER

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : BÁRBARA SCHNEIDER
DATE: 26/08/2024
TIME: 13:30
LOCAL: Campus Feliz (defesa online) -- Link: meet.google.com/nyd-dwrh-rjk
TITLE:

Evaluation of the influence of different levels of graphene carbon dots in epoxy resin by assessing thermal conductivity, density, morphology and dynamic-mechanical thermal properties (DMTA).

KEY WORDS:

carbon quantum dots; epoxy nanocomposite; thermal conductivity; structure and property relationship.

PAGES: 35
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Polímeros, Aplicações
SUMMARY:

Different amounts of graphene quantum dots (CQDs) (0, 1, 2.5, and 5 wt%) were incorporated into an epoxy matrix. The thermal conductivity, density, morphology, and dynamic mechanical thermal (DMTA) properties were reused from the study of Seibert et al. The Pearson plot showed a high correlation between mass loading, thermal conductivity, and thermal diffusivity. A poorer correlation with density and heat capacity was observed. At lower CQD concentrations (0.1 wt%), the fracture surface showed to be more heterogeneous, while at higher amounts (2.5 and 5 wt%), a more homogeneous surface was observed. The storage modulus values did not change with the CQD amount. But the extension of the glassy plateau increased with higher CQD contents, with an increase of ~40 ◦C for the 5 wt% compared to the 2.5 wt% and almost twice compared to the neat epoxy. This result is attributed to the intrinsic characteristics of the filler. Additionally, lower energy dissipation and a higher glass transition temperature were observed with the CQD amount. The novelty and importance are related to the fact that for more rigid matrices (corroborated with the literature), the mechanical properties did not change, because the polymer bridging mechanism was not present, in spite of the excellent CQD dispersion as well as the filler amount. On the other hand, thermal conductivity is directly related to particle size and dispersion.

COMMITTEE MEMBERS:
Externa à Instituição - ANA PAULA BILCK - IFRS
Presidente - 2383615 - DAIANE ROMANZINI
Interno - 1332290 - EDSON LUIZ FRANCISQUETTI
Externo à Instituição - HEITOR LUIZ ORNAGHI JUNIOR
Externo à Instituição - MATHEUS POLETTO - UCS