Banca de DEFESA: CAIO MATHEUS FERREIRA DE CARVALHO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : CAIO MATHEUS FERREIRA DE CARVALHO
DATE: 05/07/2024
TIME: 10:00
LOCAL: Auditório do Instituto de Física - ICC centro
TITLE:

Nanoscale Investigation on the Structure and Stability of Nitrogen Enriched Carbon Nanodots Dispersions.

KEY WORDS:

Carbon-dots, Nitrogen-rich Carbon Dots, Small-angle X Ray Scattering, Mass Fractal, Surface Fractal, Colloidal Stability.

PAGES: 56
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

Carbon dots are a class of 0-dimensional nanomaterials important for many applications ranging from nanomaterials for industry nanosensors as optoelectronic components, in the medical field, and in energy storage. They have gained space in the scientific community for their easy and cost-effective synthesis, optical properties, and outstanding photoluminescence. For this matter, carbon dots with nitrogen enrichment have been shown to change the inner and surface structures of the carbon dots, characterizing the well-established nitrogen-rich carbon dots (N-CDs). In this work, the structure of the N-CDs while dispersed in an aqueous medium was investigated by using synchrotron Small-Angle X Ray Scattering (SAXS) and Dynamic Light Scattering (DLS), discussing the important phenomenon of aggregation that occurs in this system. The results show that the nitrogen content inside the N-CDs leads to two types of morphology: mass fractals for high nitrogen enrichment and surface fractals for low nitrogen enrichment. Furthermore, complex and hierarchical aggregates were identified in the dispersion of N-CDs that are all stable in the pHs considered here: 2, 7, and 12. The results were interpreted using the initial structure of the N-CDs powders, which were initially investigated using X Ray Diffraction (XRD), High Resolution Transmission Electron Microscopy (HRTEM), and SAXS, as well as the surface charge mechanism that these N-CDs have. The results found can be helpful in enhancing the N-CDs applications since the relationship between the structural and optical/electronic properties is still not clear.

COMMITTEE MEMBERS:
Externa à Instituição - BARBARA BIANCA GERBELLI - UFABC
Externo ao Programa - 404882 - GERALDO JOSE DA SILVA - nullPresidente - 1218541 - JEROME DEPEYROT
Interna - 1218750 - LUANA CRISTINA WOUK