Banca de QUALIFICAÇÃO: ROSANA REIS DE LIMA ARAUJO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ROSANA REIS DE LIMA ARAUJO
DATE: 09/09/2022
TIME: 14:00
LOCAL: Defesa na forma remota pela plataforma google meet
TITLE:

NANOCELLULOSE PRODUCTION FROM MARINE MACROALGAE FROM THE COAST OF ALAGOAS VIA ACID ROUTE

KEY WORDS:

sulfuric acid, nanocompounds, algal biomass

PAGES: 123
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Bioquímicos
SUMMARY:

The search for new materials that are non-aggressive to the environment and with a renewable origin in order to develop more sustainable processes without any loss of performance and/or quality has been increasing in recent years. The market is always looking to obtain products that originate from cellulose, as it is one of the most promising and abundant materials on earth. Cellulose nanocrystals (NCC) are one of the high added value bioproducts that can be obtained from cellulose, one of the products that has been investigated due to properties such as good optical and mechanical properties, dimensional stability, high crystallinity and specific surface area. , in addition to environmental benefits. Nanostructured cellulose can be obtained from several sources, including plant fibers, agro-industrial residues and also seaweeds, which have the advantage of having lower lignin contents when compared to higher plants. However, for the NCC extraction process to be of high quality, with high yields and with lower costs, it is necessary to have a good understanding of the parameters that influence this process. In this work, cellulose nanocrystals were obtained from the macroalgae Sargassum sp. via acid hydrolysis, evaluating the physical and thermal properties of the cleavage products and the precursor material. Initially, a chemical pre-treatment of the biomass was carried out with the removal of extractives, followed by mercerization with sodium hydroxide, soon after, the treatment with hydrogen peroxide was carried out to remove impurities, lignin and hemicelluse. Then the biomass was subjected to acid hydrolysis with 64% sulfuric acid for 45min under two temperature conditions (45°C and 60°C) to obtain the NCC. The material resulting from each of the procedures was centrifuged and dialyzed in water to remove excess acid. The in natura, treated and hydrolyzed biomass was characterized by thermogravimetry (TGA), X-ray diffraction (X-DR) and scanning electron microscopy (SEM) techniques. In the next steps, two other macroalgae species will be studied, Padina sp. and Ulva sp., and the influence of hydrolysis time of 45 min and 90 min.

BANKING MEMBERS:
Presidente - 1456420 - RENATA MARIA ROSAS GARCIA ALMEIDA
Interno - 3081569 - CARLOS EDUARDO DE FARIAS SILVA
Interno - 1797785 - LUCAS MEILI
Externa à Instituição - CRISTIANE SANCHEZ FARINAS - EMBRAPA
Externo à Instituição - ANTONIO JOSÉ GONÇALVES DA CRUZ - UFSCAR