Banca de QUALIFICAÇÃO: FRANCILENE RUFINO DE LIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : FRANCILENE RUFINO DE LIRA
DATE: 12/12/2019
TIME: 14:30
LOCAL: Sala 3F1
TITLE:

Synthesis and Characterization of a Solid Polymeric Electrolyte in Form Self-Sustainable Membrane - Sodium Alginate and Lithium Perchlorate

KEY WORDS:

Sodium Alginate (AlgNa). Lithium Perchlorate (LiClO₄). Solid Polymer Electrolyte (SPE). Thermokinetic Study

PAGES: 110
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Eletroquímica
SUMMARY:

Self-sustainable membranes were synthesized used in a solid polymer electrolyte (SPE), having as host matrix or sodium alginate (AlgNa) and as site doping or perforating agent (LiClO4) in different volumes (1, 3, 5 and 7 mL). The membranes were obtained using the sol-gel synthesis method and then characterized by XRD, FTIR-ATR, SEM, TG/DTG and DSC. The diffractograms showed that the amorphous behavior of the pure sodium alginate membrane predominates in the membranes with salt. In the FTIR-ATR spectra no band shifting was observed, however, the physical interactions between the polymeric chains and the salt ions are confirmed by the variation of the area of two bands characterized as marker bands. The images obtained by SEM show that with the addition of salt, in different concentrations, to the polymer occurs a change in the surface of the membranes that, in the highest concentration, looks like agglomerates of different formats. TG / DTG curves showed the thermal behavior of the membranes showing that salt does not interfere with polymer decomposition, however, the salt decomposes at lower temperatures as its concentration in the electrolyte increases. From the TG / DTG data, a kinetic study of the thermal decomposition of the membranes was performed using the Coats - Redfern (CR) and Horowitz - Metzger (HM) methods, which suggest first order kinetics. The pre-exponential factor A and the thermal activation parameters, E *, ΔH *, ΔS * and ΔG * were obtained. Through the DSC curves it is observed that two exothermic events occur, the first related to the decomposition of the polymer while the second related to the decomposition of the salt.

BANKING MEMBERS:
Presidente - 348475 - DJALMA RIBEIRO DA SILVA
Externa ao Programa - 1149539 - MARIA GORETTE CAVALCANTE
Interna - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Interno - 1149328 - VALTER JOSE FERNANDES JUNIOR