Banca de DEFESA: LUCAS DA SILVA FERREIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LUCAS DA SILVA FERREIRA
DATE: 14/08/2023
TIME: 16:00
LOCAL: Instituto de Física
TITLE:

UV shielding in chitosan films doped with carbon quantum dots measured by wettability

KEY WORDS:

Polymeric films, Ultraviolet radiation, Carbon quantum dots, Wetting phenomenon

PAGES: 62
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUBÁREA: Física da Matéria Condensada
SPECIALTY: Equação de Estado, Equilíbrio de Fases e Transições de Fase
SUMMARY:

The present study is devoted to characterizing the optical and interfacial properties of chitosan films doped with carbon quantum dots. In particular, carbon nanoparticles are synthesized from the hydrothermal method, using methyl red dye as a precursor.
Using UV-Vis spectroscopy and optical tensiometry techniques, the photostability and wettability of polymeric films are analyzed, emphasizing the effects associated with photoexcitation of the samples with a laser in the UV region. The obtained results show that the addition of a small percentage of carbon quantum dots does not modify the wettability of the films but increases the photostability of the samples to UV radiation. Using glycerol as a test liquid during the contact angle measurements, one can observe that the wetting dynamics is not affected by the addition of carbon quantum dots, which act as an absorber center for electromagnetic radiation. Using the kinetic-molecular theory to analyze the wetting dynamics, the physical-chemical parameters that characterize the wetting phenomenon are determined. The results obtained in this work show that the addition of quantum dots can be used to improve the stability of biocompatible polymer films, making them less susceptible to UV radiation from the medium.

BANKING MEMBERS:
Presidente - 2458049 - ITALO MARCOS NUNES DE OLIVEIRA
Interno(a) - 2621034 - MARIA SOCORRO SEIXAS PEREIRA
Externo(a) à Instituição - PEDRO JUVENCIO DE SOUZA JUNIOR - IFAL