Banca de QUALIFICAÇÃO: JAINE APARECIDA DA SILVA PEREIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : JAINE APARECIDA DA SILVA PEREIRA
DATA : 10/12/2020
HORA: 13:00
LOCAL: por participação remota
TÍTULO:

SYNTHESIS AND CHARACTERIZATION OF HYBRID MATERIALS FOR APPLICATION IN FILTRATION MEMBRANE

PÁGINAS: 65
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Polímeros, Aplicações
RESUMO:

Membranes are barriers that allow the separation of materials depending on their physical and chemical properties. They present a higher performance when compared to conventional filters due the size of their surface area and pores. The main materials used to prepare the membranes present low hydrophilic properties being susceptible to fouling problems. Aiming to reduce those problems, this paper suggests the synthesis of conductive hybrid materials, polyaniline nanocomposites and graphene oxide for modification of poly (ether sulfones) membranes. The polyaniline (PANI) is a very studied intrinsic conducting polymer, because of some important characteristics such as the low cost monomer, the known polymerization process, the excellent stability in environmental conditions, and the facilities to obtain its insulating conductor altered state in a controlled way. In this way, the purpose of this paper is the synthesis and characterization of polyaniline and graphene oxide (GO) films, aiming to modify the poly (sulfone ether) membranes. To synthesize the PANI it has been used a method developed by MacDiarmid, through the use of ammonium persulfate (APS), an oxidizing agent, in different monomer:oxidizer ratios: 4:1, 2:1 e 1:1. The films was obtained using the casting technique, from a solution of polyaniline in N-methyl-2-pyrrolidone (NMP), 5 wt%. Then, the obtained films were doped by immersion using two types of acids: the hydrochloric acid (HCl) and camphor sulfonic acid (HCSA), for different time intervals. The synthesized materials were characterized by UV-Vis spectroscopy and electrically using the four-point probe technique. The obtained results showed a high influence of the oxidizing agent on the synthesis yield, with the obtained polyaniline presenting the characteristics from PANI-EB and PANI-ES (doped with HCSA) and showing the displacement of the absorption band in the visible region accompanied by the variation of its optical properties. As partial results, the PANI films obtained by casting showed electricity conduction levels compatible with films obtained in the literature in the presence of NMP after doping, the process being influenced by the immersion time on acid and the size of the acid anion. Longer immersion times and shorter anion size led to lower resistivity, with HCSA doping resulting in conductivity of the order of 10^-4 S.cm^-1 and for HCl 10 S.cm^-1.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1669182 - JOSE FERNANDO QUEIRUGA REY
Membro Titular - Examinador(a) Interno ao Programa - 1850090 - ANNE CRISTINE CHINELLATO
Membro Titular - Examinador(a) Externo ao Programa - 1073159 - EDUARDO LUCAS SUBTIL
Membro Suplente - Examinador(a) Interno ao Programa - 1305186 - SERGIO BROCHSZTAIN
Membro Suplente - Examinador(a) Externo ao Programa - 1545738 - MARCIA TSUYAMA ESCOTE