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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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.
Graphene oxide nanosheets as fillers for thermoplastic-matrix nanocomposites
2020 - MOURA, E.A.; SANTOS, B.S.; ISHIKAWA, O.; SANTANA, J.G.; BARTOLOMEI, M.R.; OLIVEIRA, R.R.
Recent studies have shown that the synthesis of graphene oxide (GO) by chemical oxidation of graphite followed by its reduction is one's the most promising routes to prepare remarkable polymer/graphene nanocomposite materials with significant improvement of properties compared to the base polymer. The addition of a very small amount of reduced graphene oxide (RGO)in a polymer can enhance its properties, with respect to electrical conductivity, barrier resistance, stiffness, abrasion resistance, mechanical resistance, and fire retardancy. Numerous approaches have been established to prepare RGO from the desoxygenation of GO. This work presents the synthesis of graphene oxide by chemical oxidation of graphite followed by its photoreduction in aqueous dispersion using UV radiation and highlights some examples of RGO/thermoplastic-matrix nanocomposites prepared by melt processing. To evaluate the potential application of thermoplastic composites prepared, the RGO's content on the morphological, mechanical and thermal properties of the as-obtained nanocomposites has been assessed. In addition, GO/RGO nanosheets were characterized by ATR–FTIR, XRD, Raman, and FE-SEM. According to the results, it can be inferred that the addition of RGO leads to a remarkable improvement in the performance of thermoplastic-matrix nanocomposites and offers a competitive solution for various potential applications.
A comparison between graphene oxide and reduced graphene oxide as reinforcement agents in polypropylene nanocomposite using irradiated polypropylene as compatibilizer
2020 - SOARES, CARLOS; SANTANA, JULYANA; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B.
Graphene is thematerial with the bestmechanical resistance ever encountered. Various types of studies have been carried out on possible applications. The use as a reinforcement in nanocomposites has shown to be a promising field, but some studies indicate that the graphene oxide (GO) and reduced graphene oxide (RGO) have better results as reinforcement, due to the functional groups,which allowa better adhesion with the matrix. This study analyzes the production of polypropylene (PP) nanocomposite comparing the use of graphene oxide (GO) and reduced graphene oxide (RGO) as fillers and irradiated polypropylene as a coupling agent.Atwin-screw extruder and injection molding machine were used to produce the nanocomposite PP reinforced with 0.2 wt% of GO and RGO by melt blending. The GO and RGO were characterized byXRDanalysis.The nanocomposite sampleswere characterized by XRD, SEM, TG, DSC and mechanical test.
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.
Development of biocomposite materials from biodegradable polymer and bio-hydroxyapatite derived from eggshells for biomedical applications
2019 - REIS, PEDRO R.S.; SANTANA, JULYANA G.; OLIVEIRA, RENE R.; RANGARI, VIJAYA K.; LOURENÇO, FELIPE R.; MOURA, ESPERIDIANA A.B.
Nowadays, significant advances have been made in the development of biodegradable polymeric materials for biomedical applications. This study aims to prepare and characterize composite materials based on PLA/PBAT, a biodegradable polymer blend, reinforced with bio-hydroxyapatite (bio-HAp). First, bio-HAp was obtained from eggshell residues by the wet precipitation method. PLA/PBAT blend with 1.5 wt% of bio-HAp was prepared by melt extrusion and injection molding process. Part of composite samples was irradiated with gamma radiation dose of 25 kGy, at room temperature and presence of air. The effects of the bio-HAp addition into the biodegradable blend were investigated by mechanical tests, XRD, DSC, FESEM, and cytotoxicity “in vitro” analysis and the correlation between the properties was discussed. In addition, the microbiological tests were carried out at irradiated and non-irradiated composite samples in order to evaluate the efficiency of the radiation dose of 25 kGy at composite materials sterilization.
Preparação e caracterização de nanocompositos EVA/ARGILA/TiO2 para a aplicação no segmento de embalagens para alimentos
2018 - MOURA, E.A.B.; BARTOLOMEI, S.S.; SANTANA, J.G.; VALENZUELA-DIAZ, F.R.; WIEBECK, H.; GUVEN, O.
O copolímero de etileno-acetato de vinila (EVA) é uma poliolefina que apresenta uma variedade de aplicações industriais, tais como cabos e fios, embalagens flexíveis, mangueiras e tubos, encapsulantes fotovoltaicos e calçados. O EVA é muito utilizado na fabricação de embalagens flexíveis para alimentos em razão das suas características de flexibilidade, tenacidade, elasticidade e transparência. O EVA vem sendo bastante utilizado para a obtenção de nanocompósitos, uma vez que o seu caráter polar pode facilitar as interações com as nanocargas adicionadas e conferir melhores propriedades mecânicas, térmicas e de barreiras a embalagem flexível processada a partir do nanocompósito quando comparadas as propriedades da embalagem de EVA puro. Neste trabalho filmes flexíveis de EVA reforçado com argila e dióxido de titânio foram preparados por extrusão, usando uma extrusora de duplarosca, seguida de extrusão plana em extrusora monorosca. Os efeitos da adição de argila e TiO2 nas propriedades dos filmes de EVA foram investigados por meio de ensaios mecânicos de tração, análises de DRX, DSC, TG, FE-SEM, TEM e UV-VIS e a correlação entre as propriedades foi discutida. Os resultados mostraram ganhos de propriedades mecânicas, térmicas e de barreira a UV do filme de EVA devido à adição de argila e dióxido de titânio. Estes resultados mostram que é possível obter ganhos de propriedades interessantes em filmes flexíveis de EVA para a aplicação em embalagens para alimentos pela adição de uma pequena quantidade de argila e de nanopartículas de dióxido de titânio.
Mechanical, thermal, morphology and barrier properties of flexible film based on polyethylene-ethylene vinyl alcohol blend reinforced with graphene oxide
2017 - SANTANA, JULYANA G.; ORTIZ, ANGEL; OLIVEIRA, RENE R.; RANGARI, VIJAY K.; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B.
Ethylene-vinyl alcohol (EVOH) copolymers are widely used in the food packaging industry as gas barrier properties to oxygen, organic solvents, and food aromas. EVOH is very sensitive to moisture and its gas barrier ability deteriorates in high relative humidity conditions. This work aims to prepare flexible films based on melt-blending high density polyethylene (HDPE) and ethylene-vinyl alcohol (HDPE/EVOH/EVA blend) reinforced with graphene oxide (GO). The HDPE/EVOH/EVA/GO flexible films were prepared by twin-screw extrusion and blown film extrusion processing. The flexible films samples were characterized by tensile tests, TG, DSC and FE-SEM analysis and the correlation between properties was discussed. In addition, the oxygen permeability tests were performed at 23 °C, 0 and 90% relative humidity using an OX-TRAN (MOCON Inc.).
Propriedades térmicas e mecânicas de filmes flexíveis de polietileno e copolímero de etileno e álcool vinílico reforçados com óxido de grafeno
2017 - SANTANA, JULYANA G.; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B.
Os copolímeros de etileno e álcool vinílico (EVOH) são uma família de resinas com excelentes propriedades de barreira a gás de grande importância para a indústria de embalagens para alimentos, o polietileno de alta densidade (HDPE) um polímero hidrofóbico que em mistura com o EVOH, agrega melhores propriedades de barreira e mecânicas a embalagem final. O objetivo deste trabalho foi estudar os efeitos da adição de óxido de grafeno (GO) nas propriedades de filmes flexíveis preparados a partir de uma blenda HDPE e EVOH (HDPE/EVOH). Que foram processados, utilizando-se uma extrusora dupla rosca corrotante, e posteriormente os materiais processados foram alimentados a uma extrusora balão de laboratório para a obtenção dos filmes flexíveis. Os filmes flexíveis foram caracterizados por meio das análises de DSC, TG, MEV e ensaios de tração e a correlação entre as suas propriedades foi discutida.
Effects on Clay addition on properties of LDPE flexible films
2017 - SANTANA, JULYANA G.; SEIXAS, M.V. de S.; ARANTES, MARIANA; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B.
Studies have indicated that the addition of nanoparticles in flexible films improves performance flexible packaging, leading to better mechanical, thermal and barrier properties. Clay is an abundant mineral, inexpensive, easy to process, and provide considerable enhancements on the properties of polymers. Titanium dioxide (TiO 2 ) is widely used for its efficiency in scattering visible light, and imparting whiteness, brightness, and high opacity when incorporated into a plastic formulation. Low density polyethylene (LDPE) is generally used as a packaging material due to its good resistance, easy processing, low cost and high hardness. The objective of this study was to evaluate the effects of clay and TiO 2 nanoparticles addition on the properties of LDPE flexible films. LDPE with 1 wt % of TiO 2 addition and 1-3 wt. % of green Brazilian Clay, from Cubati, Pb, Brazil were prepared by melt extrusion process, using a twin-screw extruder Haake Rheomex P332 with 16 mm and L/D = 25, from Thermo Scientific. Then the LDPE/Clay nanocomposite was transformed into thin films using an extrusion blown film, single screw machine with 25 mm diameter and specimen test samples were obtained. The specimen samples were characterized by mechanical tests, UV-VIS, DSC, TG and FE-SEM analysis.
Biodegradable polymer blends reinforced with bio-hydroxyapatite nanoparticle - preparation and characterization
2017 - REIS, PEDRO R.S.; SANTANA, JULYANA G.; OLIVEIRA, RENE R.; RANGARI, VIJAYA K.; MOURA, ESPERIDIANA A.B.
Nowadays significant advances have been made in the development of biodegradable polymeric materials for biomedical applications. The purpose of this study was to preparation and characterization of biodegradable polymer blend reinforced with bio-hydroxyapatite nanoparticle from eggshell by sonochemical method. Biodegradable polymer blends based on PLA (Poly(lactic acid)) and the PBAT (butylene adipate-co-terepthalate)) reinforced with 1-5 wt. % of bio-hydroxyapatite were prepared by melt extrusion, using a twin screw extruder and injection molding machine to obtain specimen test. The effects of the bio-hydroxyapatite addition on properties of PLA/PBAT biodegradable blend were investigated by tensile tests, XRD, DSC, TG and SEM-FEG analysis and the correlation between the results was discussed.