ESPERIDIANA AUGUSTA BARRETOS DE MOURA

ESPERIDIANA AUGUSTA BARRETOS DE MOURA

(Fonte: Lattes)

Resumo

Graduated in Chemical Engineering at Faculdade Oswaldo Cruz (1983), Master in Nuclear Technology - Applications at IPEN / USP (1999), Ph.D. in Nuclear Technology - Applications at IPEN / USP (2006) and Post-Doctorate at Center for Advanced Materials ( T-CAM) from Tuskegee University, AL, USA. The main lines of research are: Synthesis of metallic nanoparticles; Obtaining and characterization of nanoparticles from mineral activity and agroindustry residues; Micro and nanofiller functionalization; Synthesis and reduction of graphene oxide; Development and modification of composite materials based on conventional and biodegradable polymers with vegetable fibers, micro and nanofillers of renewable origin; Development of biodegradable, active and intelligent plastic packaging for food, cosmetics, medical and pharmaceutical products; Development of conductive polymeric materials; Development of biomaterials for application in the regeneration of bone and dental tissue. (Text obtained from the Currículo Lattes on October 8th 2021)

Possui graduação em Engenharia Química pela Faculdade Oswaldo Cruz (1983), mestrado em Tecnologia Nuclear ? Aplicações pelo IPEN/USP (1999), doutorado em Tecnologia Nuclear ? Aplicações pelo IPEN/USP (2006) e Pós-Doutorado no Center for Advanced Materials (T-CAM) da Tuskegee University, AL, USA. As principais linhas de pesquisa são: Síntese de nanopartículas metálicas; Obtenção e caracterização de nanopartículas a partir de resíduos da atividade mineral e da agroindústria; Funcionalização de micro e nanocargas; Síntese e redução de óxido de grafeno; Desenvolvimento e modificaçao de materiais compósitos baseados em polímeros convencionais e biodegradáveis com fibras vegetais, micro e nanocargas de origem renovável; Desenvolvimento de embalagens plásticas biodegradáveis, ativas e inteligentes para alimentos, cosméticos, produtos médicos e farmacêuticos;Desenvolvimento de materiais poliméricos condutores; Desenvolvimento de biomateriais para aplicação na regeneração de tecidos ósseos e dentários. (Texto extraído do Currículo Lattes em 08 out. 2021)

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Influence of reinforcing efficiency of clay on the mechanical properties of poly(butylene terephthalate) nanocomposite
2023 - COLOMBO, MARIA A.S.; DIAZ, FRANCISCO R.V.; KODALI, DEEPA; RANGARI, VIJAYA; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B.
In contrast to traditional fillers, clay, in particular, natural smectite clay, represents an environmentally significant alternative to improve the properties of polymers. Compared to conventional nanofillers, smectite clay can effectively enhance the physical and mechanical properties of polymer nanocomposites with a relatively small amount of addition (<5 wt%). The present study focuses on investigating the reinforcing efficiency of different amounts (up to 5 wt%) of a natural Brazilian smectite clay modified (MBClay) on the mechanical properties of poly(butylene terephthalate) (PBT) nanocomposites and also evaluates the correlation between MBClay addition and the mechanical and thermal behaviors of the PBT/MBClay nanocomposites. Natural Brazilian clay modified by the addition of quaternary salt and sodium carbonate (MBClay) was infused into the PBT polymer by melt extrusion using a twin-screw extruder. It was found that the best properties for PBT were obtained at 3.7 wt% of modified BClay. Tensile strength at break exhibited increased by about 60%, flexural strength increased by 24%, and flexural modulus increased by 17%. In addition, an increase in the crystallinity percentage of PBT/BClay nanocomposite was confirmed by DSC and XRD analysis, and a gain of about 45% in HDT was successfully achieved due to the incorporation of 3.7 wt% of MBClay
Synergistic effect of e-beam irradiation and graphene oxide incorporation on thermal, mechanical, and barrier properties of poly (ethylene-co-vinyl alcohol) film
2022 - SANTANA, JULYANA G.; AKBULUT, MESHUDE; TEMPERINI, MARCIA L.A.; RANGARI, VIJAY K.; GUVEN, OLGUN; MOURA, ESPERIDIANA
Graphene and its derivatives, such as graphene oxide (GO), have attracted enormous interest from academia and industry because of its unique electrical, mechanical, and thermal properties, which can lead to enhanced material performance. In the present study, low contents of GO were incorporated into the poly (vinyl alcohol-co-ethylene) (EVOH). First, the GO was prepared by chemical oxidation of graphite employing a modified Hummer's method. The GO content of 0.1–0.3 wt % was incorporated in the EVOH matrix using a twin-screw extruder and extrusion blown film process to prepare flexible films. EVOH/GO film samples were irradiated at 100 kGy, using a 1.5 MeV electron-beam accelerator, at room temperature, in the presence of air. GO was characterized by XRD, ATR-FTIR, FE-SEM, and TEM analysis. XRD patterns of GO show a sharp reflection peak at 2θ = 10° (d001) corresponding to a d-spacing at 8.84 Å, characteristic of GO. The non-irradiated and irradiated samples were characterized by XRD, FEG-SEM, TG, DSC, oxygen transmission rate (OTR), UV/VIS analysis, and tensile tests. EVOH/GO nanocomposite films had an improved oxygen barrier, while also retaining fairly good transparency. As an effect of e-beam irradiation, the thermal, mechanical, and barrier behaviors of the nanocomposite films were even better than non-irradiated film samples, and obviously better than neat EVOH. Thus, the incorporation of low contents of GO followed by e-beam radiation treatment might be an interesting alternative to produce packaging materials based on EVOH with outstanding performance even under very humid conditions.
Investigation of the effect of titanium dioxide and clay grafted with glycidyl methacrylate by gamma radiation on the properties of EVA flexible films
2020 - BARTOLOMEI, SUELLEN S.; SANTANA, JULYANA G.; DIAZ, FRANCISCO R.V.; KAVAKLI, PINAR A.; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B.
Many studies report that nanocomposites obtained by dispersion of a small amount nanofiller into the polymer have remarkable improvements achieved in the mechanical and physical properties. However, in order to achieve this great improvement in properties, it is necessary that the nanofillers be dispersed homogeneously into the polymeric matrix. Often this dispersion is difficult to achieve due to the high interfacial energy of the nanoparticles present. This study reports the effect of gamma irradiation induced graft of glycidyl methacrylate (GMA) onto the surface of TiO2 and Clay nanofillers to improve their dispersion into the EVA matrix. The physical and mechanical properties of Ethylene-vinyl acetate copolymer (EVA) flexible films with these nanoparticles were studied. EVA nanocomposite with adding of the different amount of TiO2 and modified montmorillonite clay grafted and un-grafted with glycidyl methacrylate (GMA) using gamma irradiation have been prepared by melt extrusion. The nanocomposite flexible films were produced using a flat die extrusion process. The PGMA-grafted nanofillers were characterized by XRD and TEM analysis. The flexible films were characterized by Tensile tests, ATR–FTIR, UV–VIS, XRD, TG, and FE-SEM analysis to understand the nature of the interaction between the nanofillers and EVA matrix. The results showed that the addition of PGMA-grafted TiO2 and Clay nanofillers into EVA matrix improved the bonding between the nanofillers and matrix. It was also found that the PGMA-grafted nanofillers could be well dispersed into an EVA matrix in contrast to that of un-grafted. The tensile strength and modulus of the resulting EVA/TiO2-PGMA enhanced in comparison to that of un-grafted TiO2. The EVA/Clay-PGMA had slightly decreased tensile strength comparable to that of EVA/Clay but had considerably improved elastic modulus. In addition, the flexible films based on TiO2 exhibited high UV–Vis light absorption with energy gap shifted to the visible region. The results demonstrated that TiO2 and Clay nanofillers grafted with GMA by gamma radiation can be used to prepare EVA flexible films with improved bonding between the nanofillers and matrix and, consequently, enhanced properties for food and cosmetic packaging application.
Short vegetal-fiber reinforced HDPE - A study of electron-beam radiation treatment effects on mechanical and morphological properties
2014 - FERREIRA, MAIARA S.; SARTORI, MARIANA N.; OLIVEIRA, RENE R.; GOUVEN, OLGUN; MOURA, ESPERIDIANA A.B.
Preparation and characterization of electron-beam treated HDPE composites reinforced with rice husk ash and Brazilian clay
2014 - ORTIZ, A.V.; TEIXEIRA, J.G.; GOMES, M.G.; OLIVEIRA, R.R.; DIAZ, F.R.V.; MOURA, E.A.B.