Banca de QUALIFICAÇÃO: PLINIO COELHO VITAMÉ

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : PLINIO COELHO VITAMÉ
DATE: 21/03/2024
TIME: 13:00
LOCAL: https://conferenciaweb.rnp.br/sala/juliana-255
TITLE:

 PRODUCTION AND CHARACTERIZATION OF PEGZNO-TYPE NANOCOMPOSITES OBTAINED BY IN SITU MICROWAVE-ASSISTED SYNTHESIS OF ZINC OXIDE NANOSTRUCTURES ON POLYETHYLENE GLYCOL

PAGES: 66
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Físico Química Inorgânica
SUMMARY:

Polyethylene glycol (PEG) is an oligomer produced by ethylene oxide polymerization, which is water soluble as well as soluble at several organic solvents, besides the fact that it is biocompatible, nontoxic and nonimmunogenic. Due to this fact, it is used in several areas, highlighting the pharmaceutical formulations as excipients, and cosmetic preparations, where it has the function, among other possibilities, of emollient. Zinc oxide is an inorganic semiconductor of low toxicity, low cost, high physical and chemical stability, UV radiation absorber, presenting also antimicrobial action. Due to its properties ZnO is also used in cosmetic formulation as sunscreen and nappy rash ointment. One challenge for formulations containing PEG and ZnO is the compatibilization of both chemicals. To surpass its issue it is reported here a microwave assisted solvothermal method for PEG-ZnO nanocomposite obtention using PEG, a hydroxide and a zinc salt for ZnO. This route excludes the calcination step (common for ZnO synthesis and what would eliminate the PEG), in a way to obtain ZnO nanoparticles (NPs) suspension in PEG after the end of the synthesis. A design of experiment (DoE) of response surface kind was carried out to evaluate the impact of the reaction parameters time, temperature and heating ramp over the ZnO morphology and crystallinity and over the PEG oxidation. Results show that it was possible to obtain ZnO NPs with Wurtzite structure with same crystallinity and crystallite size regardless of the synthesis parameters employed. Electronic microscopy imagens reveal that time, temperature and heating ramp have impact over ZnO NPs morphology, while also showing a dissolution/recrystallization grow mechanism. Finally, colorimetric analysis has shown that PEG oxidation is increased by increasing reaction time and temperature.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 2351974 - JULIANA DOS SANTOS DE SOUZA
Membro Titular - Examinador(a) Externo ao Programa - 1671275 - DERVAL DOS SANTOS ROSA
Membro Titular - Examinador(a) Externo à Instituição - RONDES FERREIRA DA SILVA - CEETEPS
Membro Suplente - Examinador(a) Interno ao Programa - 1864481 - HUEDER PAULO MOISES DE OLIVEIRA