Banca de DEFESA: DÊNIS GIOVANNI DE MEDEIROS DANTAS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : DÊNIS GIOVANNI DE MEDEIROS DANTAS
DATE: 24/08/2023
TIME: 09:00
LOCAL: Plataforma Google Meet
TITLE:

Mechanical Properties of Naphthylenes

KEY WORDS:

Carbon, Two-Dimensional, Stress, Uniaxial Strain, Defects, Vacancy, Graphene, Naphthylene, Mechanical
Properties, Density Functional Theory, Molecular Dynamics.

PAGES: 75
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

Since its discovery and synthesis in 2004, graphene has been gaining increasing attention in the scientific community due to its
broad applicability in various technological fields. Over the years, new carbon-based two-dimensional materials have been
discovered, and one of the most recent ones, discovered in 2019, is the Naphthylene. This material consists of a family of three
structures known as alpha, beta, and gamma. In this study, we investigate the mechanical properties of these materials through

uniaxial deformation using two distinct methods: (i) classical molecular dynamics (MD) employing the LAMMPS (Large-
scale Atomic Molecular Massively Parallel Simulator) program in conjunction with the Tersoff three-body interatomic

potential; and (ii) quantum simulations based on density functional theory (DFT) using the SIESTA code. We compare the
results obtained from both methods and analyze how vacancy defects in different carbons affect the mechanical properties of
naphthylenes. We found that the results obtained with MD for naphthylene-alpha show good agreement with the quantum
method. The naphthylene-beta structure exhibited the highest elastic constant and the least susceptibility to failure, comparable
to graphene. Naphthylene-gamma was found to be the least resistant to fractures. None of the studied materials are isotropic;
they exhibit different elastic constants and distinct non-uniform stress distributions when deformed in different directions.

COMMITTEE MEMBERS:
Interno - 1345774 - CLAUDIONOR GOMES BEZERRA
Presidente - 2411793 - LEONARDO DANTAS MACHADO
Externo à Instituição - SERGIO ANDRÉ FONTES AZEVEDO - UFPB
Interno - 1352009 - UMBERTO LAINO FULCO