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)

Página do item completo

Resultados de Busca

Agora exibindo 1 - 10 de 14

Enhanced miscibility of PBAT/PLA/lignin upon γ-irradiation and effects on the non-isothermal crystallization
2022 - BARROS, JANETTY J.P.; SOARES, CARLOS P.; MOURA, ESPERIDIANA A.B. de; WELLEN, RENATE M.R.
Lignin is natural and renewable polymer, the second most abundant on Earth. Properly used it can reduce synthetic and oil based materials in addition to contributing to the biodegradable systems. In this work, the kraft lignin was subjected to gamma radiation at absorbed doses of 30, 60, and 90 KGy in order to increase the interaction with “Poly(butylene adipate-co-terephthalate) (PBAT)/Poly(lactic acid) (PLA)” blend (Ecovio®). PBAT/PLA/lignin blends with 10% of the weight of lignin were produced by extrusion using twin-screw extruder and characterized by Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), and Field emission scanning electron microscopy (FE-SEM). FTIR spectra showed partial miscibility between PBAT/PLA and lignin, most due to the hydrogen bond between PBAT/PLA carbonyl and lignin hydroxyl, being intensified in irradiated lignin compounds. As evidenced on DSC scans, in PBAT/PLA/irradiated lignin the crystallization peak was shifted to lower temperatures and the crystallization rate decreased. Crystallization kinetics was modeled using Pseudo Avrami, and isoconversional models of Friedman and Vyazovkin. Pseudo-Avrami displayed linearity deviation at beginning and crystallization ending due to the nucleation and secondary crystallization, while from Friedman and Vyazovkin the activation energy (Ea) was higher for PBAT/PLA/irradiated lignin 30 KGy, characterizing crystallization with higher energy consumption. FE-SEM images showed better dispersion and miscibility in PBAT/PLA/irradiated lignin. The results indicate that the irradiation of Kraft lignin promotes miscibility and compatibility of PBAT/PLA/lignin.
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.
Influence of electron-beam irradiation on the properties of LDPE/EDPM blend foams
2018 - SANTANA, JULYANA; SEIXAS, MARCUS V. de S.; RANGARI, VIJAY; VALENZUELA-DIAZ, FRANCISCO; WIEBECK, HELIO; MOURA, ESPERIDIANA
Closed-cell polyethylene (PE) foams have been extensively used in many applications such as packaging, transportation, sports, construction, and agriculture because of their variety of properties including light weight, chemical resistance, thermal and electrical insulation. The objective of this study is to evaluate the influence of electron-beam irradiation on the properties of LDPE/EPDM blend foams. The LDPE/EPDM blend (80/20 wt%) were prepared by melt extrusion, using a twin-screw extruder machine. The foam structure of LDPE/EPDM blends was obtained by melt extrusion process, using a special single screw for foaming with 1.5 wt% of foaming agent as blowing agent. The foam samples were irradiated by electron-beam at radiation dose of 25, 50, 75 and 100 kGy and submitted to heating in an oven at 100 °C. The specimen tests samples of irradiated and non-irradiated foams were submitted to mechanical tests, DSC, TG analysis and density measurement.
Comparison between HDPE/clay and HDPE/piassava fiber/clay treated by electron beam radiation
2013 - ORTIZ, ANGEL; ESCANHOELA, CORDELIA M.F.; GOMES, MICHELLE; OLIVEIRA, RENE R.; DIAZ, FRANCISCO R.V.; MOURA, ESPERIDIANA A.B.
This work evaluates changes in morphological, mechanical and thermo-mechanical properties of electron-beam irradiated HDPE/nanoclay and HDPE/Piassava fiber/nanoclay. Material samples irradiated with 100 and 200 kGy using a 1.5 MeV electron beam accelerator (room temperature, presence of air) were submitted to tensile, flexural, and HDT tests. MFI, SEM and XRD analyses were carried out. Correlation between properties was discussed. Results showed that incorporation of piassava (Attalea funifera Mart) fiber and nanoclay, followed by irradiation represented significant gain in thermo-mechanical properties. Changes in surface morphology and reduction in MFI were observed. In conclusion, it may be claimed that the incorporation of piassava fiber in small size particles and nanoclay in the HDPE followed by electron-beam irradiation effectively improved the polymer properties and led to materials with superior properties suitable for several industrial applications.
Comparative study of the sugarcane bagasse FIBER/HDPE composite properties using electron-beam and gamma radiation treatments
2012 - PEREIRA, AMANDA C.S.; CHINELLATO, ANNE C.; SORIA, ALEJANDRA T.; ABREU, ANIBAL V.; DEL MASTRO, NELIDA L.; MOURA, ESPERIDIANA A.B.
This work presents a comparative study of the thermo-mechanical and morphological properties of sugarcane bagasse fiber/HDPE composite treated with electron-beam and gamma radiation. The composite samples obtained by extrusion and injection molding processes were irradiated at 50 and 90 kGy using either a 1.5 MeV electron beam accelerator or gamma irradiator EMI-9, at room temperature in presence of air. The irradiated and non-irradiated samples were submitted to mechanical and MFI tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), sol-gel analysis and X-Rays Diffraction (XRD) and the correlation between their properties was discussed. Improvement of the bagasse fiber/HDPE composite properties, using electron-beam or gamma radiation, was found.
Electron-beam irradiation effect on thermal and mechanical properties of nylon-6 nanocomposite fiber infused with diamond and diamond coated carbon nanotubes
2016 - IMAM, MUHAMMAD A.; JEELANI, SHAIK; RANGARI, VIJAYA K.; GOMES, MICHELLE G.; MOURA, ESPERIDIANA A.B.
Changes in physicochemical, morphological and thermal properties of electron-beam irradiated ethylene-vinyl alcohol copolymer (EVOH) as a function of radiation
2009 - NOGUEIRA, B.R.; ANGEL, V.O.; MOURA, E.A.B.
Efeito da radiacao por feixe de eletrons sobre as propriedades mecanicas do polietileno de alta densidade
2009 - SHIMAZAKI, KLEBER; CHINELLATO, ANNE; MOURA, ESPERIDIANA A.B.
Espumas ceramicas obtidas a partir da pirolise de polissiloxano e carga ativa de Al e Si
2003 - ROCHA, R.M.; MOURA, E.A.B.; BRESSIANI, J.C.; BRESSIANI, A.H.A.
Obtenção de espumas cerâmicas no sistema Si-Al-O-C-N a partir de polissiloxano irradiado com feixe de elétrons
2002 - ROCHA, R.M.; MOURA, E.A.B.; MORI, M.N.; BRESSIANI, J.C.; BRESSIANI, A.H.A.
Neste trabalho é apresentado um novo método de obtenção de espumas cerâmicas no sistema Si-Ak 0-C-N a pa rt ir da pirólise de precursores poliméricos, polimetilssiloxano- PMS, e PMS (70 % em vol) com carga ativa de alumínio e silício. Amostras compactadas destes materiais são irradiadas com feixe de elétrons à dose de 7MGy. Durante a irradiação ocorrem os processos de reticulação e degradação liberando produtos voláteis gerando porosidade. Esta espuma é então submetida a pirólise a 1500 °C por 2 horas em atmosfera de argônio ou nitrogênio, resultando em espumas cerâmicas com fase amo rfa, para as amostras contendo somente o polissiloxano e fases cristalinas covalentes para as amostras contendo polissiloxano mais carga ativa. A mo rfologia das espumas foi mantida após a pirólise, apresentando estruturas de células abe rtas bem definidas, com densidade volumétrica de aproximadamente 0,5 g/cn1 e tamanho de célula variável (30 a 300 um).