Banca de DEFESA: SIMONE NASCIMENTO DA SILVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : SIMONE NASCIMENTO DA SILVEIRA
DATE: 20/08/2026
TIME: 13:30
LOCAL: Remota - Google Meet
TITLE:

“ Poly(vinylidene fluoride) (PVDF) and carbon black (CB) composites for electromagnetic shielding ”

KEY WORDS:

Composites, conductive filler, electromagnetic shielding

PAGES: 75
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Polímeros, Aplicações
SUMMARY:

Conductive composites are materials composed of an insulating Polymer matrix and conductive fillers, such as carbon black, carbon nanotubes, or graphene, which improve their electrical properties and have both civilian and military applications. This study aims to develop and characterize poly(vinylidene fluoride) (PVDF) composites containing carbon black (NF) for electromagnetic shielding applications. PVDF/NF composites were prepared with compositions of 90/10, 85/15, and 80/20 by microextruder at 230 °C. The speciments were then injection molded at the same temperature for characterization. According to the preliminary FT-IR results of the PVDF/NF blends, a reduction in the intensity of the band at 840 cm-1 was observed, indicating a decrease in the β- crystalline phase and lower structural organization of the polymer chains. Rheological analyses revealed that addition of carbon black increased the complex viscosity of the composites compared to pure PVDF, with all samples showing pseudoplastic behavior, characterized by a decrease in viscosity as the frequency increased. The micrographs showed that the composites containing 20% carbon black (NF) exhibited better particle dispersion and the formation of a conductive network within the PVDF matrix. In addition, the alternating current (AC) conductivity increased with carbon black, enhancing electrical conduction. Finally, the electromagnetic shielding tests indicated that the shielding efficiency increases with both the carbon black content and the material thickness, with the 80/20 PVDF/NF sample showing the best performance, reaching approximately -25 dB (1 mm) and -38 dB (3 mm). Preliminary results indicate that PVDF/NF composites are promising materials for electromagnetic shielding applications, with potential use in submarine coatings to reduce radar detection and in medical devices, such as pacemakers, to minimize electromagnetic.

COMMITTEE MEMBERS:
Presidente - 1148731 - KETLY PONTES SOARES
Interno - 3103346 - JOAO VICTOR NICOLINI
Externa à Instituição - JESSICA PEREIRA SOARES DA SILVA - UFRJ