Banca de DEFESA: MARCUS VINICIUS GOMES PAIXAO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : MARCUS VINICIUS GOMES PAIXAO
DATA : 17/05/2019
HORA: 09:00
LOCAL: Sala de aula do LAPET
TÍTULO:

EVALUATION OF THE POTENTIAL OF MAGNETIC/THERMORESPONSIVE CHITOSAN MICROSPHERES DECORATED WITH POLY (N-isopropylacrylamide) IN OILY WATER TREATMENT

PALAVRAS-CHAVES:

microspheres; chitosan; PNIPAM; thermoresponsive; oily water

PÁGINAS: 116
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Orgânica
ESPECIALIDADE: Polímeros e Colóides
RESUMO:

Smart microspheres capable of responding to magnetic fields and temperature changes were prepared by encapsulating magnetic nanoparticles into cross-linked chitosan microspheres followed by poly(N-isopropylacrylamide) (PNIPAM) brushes formation on their surfaces (MCM-PNIPAM). The synthetized microspheres were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), thermogravimetry (TG) and differential scanning calorimetry (DSC). While most studies have focused on the graft copolymerization reaction between chitosan and NIPAM to get a soluble particle, the main finding of this study was to improve the lipophilicity of magnetic crosslinked chitosan microspheres with PNIPAM brushes, in order to be used in oily water treatment as a solid adsorbent. In addition, we applied MCM-PNIPAM associated to PNIPAM homopolymer in an oil removal process. Commonly, oily water composition from an oil well is characterized by high salinity and high oil content. Therefore, it was investigated in this paper the PNIPAM thermoresponsive behavior in presence of salts (NaCl and CaCl₂), as well as the oil removal efficiency due to the MCM-PNIPAM particles clustering effect above the aggregation temperature of PNIPAM. The thermoresponsive behavior of MCM-PNIPAM was confirmed by the sharp transition phase on DSC curves. The initial investigation of oil removal efficiency was performed to the synthesized microspheres with values higher than 97% for MCM-PNIPAM above the PNIPAM aggregation temperature. On the other hand, the results showed that the time is an important parameter to obtain higher oil removal mainly due to the salinity effect, and the presence of PNIPAM homopolymer chains can give significant advantages compared to the performance of individual MCM-PNIPAM microspheres.

MEMBROS DA BANCA:
Interno - 1198847 - JOSE LUIS CARDOZO FONSECA
Interna - 2212519 - JULIANA DE SOUZA NUNES
Externa à Instituição - LUZIA PATRICIA FERNANDES DE CARVALHO GALVAO - UnP
Externa à Instituição - MARCOS ANTONIO VILLETTI - UFSM
Presidente - 1149440 - ROSANGELA DE CARVALHO BALABAN