Banca de DEFESA: ANA KAROLYNE LOBO BEZERRA ABE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANA KAROLYNE LOBO BEZERRA ABE
DATE: 28/07/2025
TIME: 14:00
LOCAL: Auditório do Laboratório de Cimentos da UFRN
TITLE:

OPTIMIZATION OF SILICA MICROCAPSULES SYNTHESIS FOR SELF-REPAIR: REVISITING THE STÖBER METHOD.

KEY WORDS:

Microcapsules; Self-healing; Smart materials; Stöber

PAGES: 95
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Polímeros, Aplicações
SUMMARY:

The Stöber method is one of the most widely used procedures in the synthesis of silica nanoparticles due to its high efficiency and control over particle dimensions. Silica nanoparticles, because of their unique physical and chemical properties, have been applied in various fields. This versatility highlights the importance of the Stöber method as a fundamental technique in the production of nano- and microparticles of silica for advanced applications such as self-repair. Self-healing materials have been developed to promote autonomous recovery and extend the service life of structures. These materials incorporate advanced technologies, such as microcapsules containing specific chemical components, which rupture when a crack occurs, releasing chemical agents that interact with other elements of the material to fill the cracks and restore the integrity of the structure. Therefore, this work aims to reproduce silica microcapsules for crack self-repair and to optimize the synthesis conditions of the microcapsules by encapsulating epoxy resin and methyl-ethyl-ketone peroxide using the Stöber method, adapted by Oliveira (2024). The methodology was divided into two stages: in the first, silica microcapsules were synthesized based on the Stöber method, using reagents such as tetraethyl orthosilicate (TEOS), hydrochloric acid (HCl), epoxy resin, and PMEK, followed by centrifugation, washing, and drying processes. In the second stage, these microcapsules were analyzed using SEM and EDS to assess their morphological conditions and to determine the optimal synthesis and application conditions. The results obtained were satisfactory, demonstrating the effectiveness of the microcapsule synthesis procedure. The importance of strictly controlling factors such as temperature, magnetic stirring, reaction time, and sphere durability during the
process was highlighted. Additionally, the mixing method within the cementitious matrix ensured efficient dispersion, contributing to the uniformity and performance of the material.

 

COMMITTEE MEMBERS:
Presidente - 1298936 - ANTONIO EDUARDO MARTINELLI
Interno - 1804366 - JÚLIO CÉZAR DE OLIVEIRA FREITAS
Externo ao Programa - ***.531.844-** - RAFAEL DA SILVA FERNANDES - UFRN
Externo à Instituição - GLAUCO SOARES BRAGA - IFRN