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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Effectiveness of modified lignin on poly(butylene adipateco-terephthalate)/poly(lactic acid) mulch film performance
2023 - BARROS, JANETTY J.P.; OLIVEIRA, RENE R.; LUNA, CARLOS B.B.; WELLEN, RENATE M.R.; MOURA, ESPERIDIANA A.B.
In this work, the biodegradable poly(butylene adipate-co-terephthalate) (PBAT)/ poly(lactic acid) (PLA) blend (ECOVIO®) and lignin, a renewable and biodegradable natural polymer with high UV absorption and modified by gamma radiation were used to produce agriculture mulch films. Lignin was gammairradiated at 30 and 60 kGy. The irradiated and non-irradiated lignin content of 2 wt% was incorporated into PBAT/PLA blend matrix using a twin-screw extruder and extrusion blown film to prepare flexible films. PBAT/PLA/LIGNIN films were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), tensile tests, contact angle, and UV–Vis analysis. FTIR spectra showed partial miscibility between PBAT/PLA and lignin, being intensified in irradiated lignin compounds. The DSC and XRD results confirmed that the degree of crystallinity of the blends was not significantly influenced by lignin addition. FE-SEM images showed better dispersion and miscibility in PBAT/PLA/Irradiated lignin. Miscibility improvement provided by irradiated lignin promoted better mechanical properties, mainly with lignin irradiated at 60 kGy. PBAT/PLA/LIGNIN films containing 2 wt% showed excellent UV-barrier property and greater hydrophobicity. Summing up, incorporation of low contents of irradiated lignin could be an interesting alternative to produce biodegradable UV-blocking agriculture mulch films.
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.
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.
A residue-free and effective corncob extrusion pretreatment for the enhancement of high solids loading enzymatic hydrolysis to produce sugars
2022 - JOSE, ALVARO H.M.; MOURA, ESPERIDIANA A.B.; RODRIGUES JUNIOR, DURVAL; KLEINGESINDS, EDUARDO K.; RODRIGUES, RITA C.L.B.
To convert biomass into biofuel, pretreatment is the first stage required to de-structure lignocellulose – twin-screw extrusion is one of the viable pretreatment technologies. The enzymatic hydrolysis of corncobs pretreated with twin-screw extrusion to obtain sugar was evaluated. Corncob extrusion (115–130 °C; 14 rpm) was enhanced through the employment of additives (water and glycerol, 25:25, % w/w). By reproducing the response surface methodology (RSM) technique, the maximized glucose productivity (0.69 g L−1 h−1) and conversion of cellulose to glucose (90.4 % w/w), as well as hemicellulose to xylose and arabinose (44.0 % w/w) were established with the dosage of the commercial enzymatic complex Cellic Ctec2 (32 FPU/gdry lignocellulosic material) and solids loading (17.8 % w/w). Total sugar yield was of 471 kg (glucose 323 kg; xylose and arabinose 148 kg) for a dried corncob ton. Kinetic constants of the Michaelis-Menten model, Vmax and Km, for converting cellulose to glucose were of 6.00 % (w/w)/h and 22.59 gcellulose/Lsolution, respectively. A residue-free and effective corncob extrusion pretreatment enhanced high solids loading enzymatic hydrolysis to achieve a glucose-rich solution.
Recycling expanded polystyrene with a biodegradable solvent to manufacture 3D printed prototypes and finishing materials for construction
2022 - BARTOLOMEI, SUELLEN S.; SILVA, FELIPE L.F. da; MOURA, ESPERIDIANA A.B. de; WIEBECK, HELIO
The amount of plastic waste generated is causing damage to the environment, such as sea and soil pollution, and one of the alternatives for disposing of polymers is recycling. This work proposes recycling expanded polystyrene using a biodegradable solvent, its plastification with glycerol, and the preparation of the composite with post-consumer recycled gypsum for applications to manufacturing by 3D printing and for finishing materials for construction. Specimen for tensile testing and shore D hardness were prepared by injection process and by 3D printing. In addition, Thermogravimetric (TG), Fourier-transform infrared spectrometry (FTIR), Differential scanning calorimeter, Scanning electron microscope (FESEM) analyses, and flame propagation tests were also carried out. TG and FTIR analyses show that the recycling process did not degrade the material, and the addition of glycerol and gypsum improved the thermal stability of the composite. The mechanical properties of the injected and 3D printed samples with gypsum were similar, due to the dimensional stability of the manufactured filament, which improved the speed and quality of the specimen printing. The increase in ductility and the reduction in the glass transition temperature showed that the recycled expanded polystyrene (RPS) were effectively plasticized with the addition of 2 wt% glycerol, preserving their flame self-extinguishment when subjected to the flame propagation test. Due to these properties, the plasticized RPS can be used to manufacture articles for finishing in civil construction, and the RPS composite can be used to manufacture 3D printed prototypes.
Development of sustainable food packaging material based on biodegradable polymer reinforced with cellulose nanocrystals
2022 - ANDRADE, MARCIO S.; ISHIKAWA, OTAVIO H.; COSTA, ROBSON S.; SEIXAS, MARCUS V.S.; RODRIGUES, RITA C.L.B.; MOURA, ESPERIDIANA A.B.
The increased environmental impact and sustainability issues related to conventional food packaging have gained attention and led to a global concern. The massive consumption of conventional food packaging has increased disposal of non-eco-friendly packaging waste, severely damaging the environment. The replacement by sustainable packaging is an important alternative to reduce the enormous volume of plastic waste. In this work, bionanocomposite films composed of PBAT/PLA blend and cellulose nanocrystals (CNCs) extracted from agro-waste were investigated. Characterization of CNCs confirmed that nanocrystals were obtained. Bionanocomposite films presented better hydrophobic character and thermal stability than the blend film. In addition, the tensile strength, elongation at break, and Young's modulus was around 52%, 29%, and 118%, respectively, higher than blend films. These mechanical values were comparable to values of commercial plastic materials that are extensively used in food packaging. Thus, the prepared bionanocomposite films might be an interesting alternative to produce sustainable food packaging materials.
Synergistic effect of polylactic acid(PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blend and cellulose nanowhiskers for sustainable packaging applications
2020 - MOURA, E.A.; SANTOS, B.S.; OLIVEIRA, R.R.; RODRIGUES, R.C.
Conventional food packaging is in general, not recyclable, based on practically undegradable petroleum-derived polymers, and consequently not selectively collected. Concerns over their environmental impact and sustainability issues posed by their production and disposal and trends have increased interest and driven the effort to generate biobased and biodegradable packaging to replace or complement the conventional ones. The aims of this work are to investigate the development of biocomposite films composed of biodegradable polylactic acid(PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blend and cellulose nanowhiskers extracted from agro-waste and evaluate their potential use in sustainable food packaging application. Biocomposite films based on biodegradable PLA/PBAT blend containing 1-2 wt. % of cellulose nanowhiskers extracted from agro-waste were prepared by melt extrusion, using a twin-screw extruder machine and blown extrusion process. To evaluate the potential use in food packaging applications, the cellulose nanowhiskers' content on the morphological, mechanical and thermal properties of the as obtained biocomposite films has been assessed. In addition, cellulose nanowhiskers were characterized by TEM, DLS, XRD, and TG. The results showed that cellulose nanowhiskers addition leads to an important increase in thermal degradation temperature, melting enthalpy and tensile properties of biocomposite films. The increases in the melting enthalpy can be attributed to the increase in the crystallinity of PBAT/PLA biocomposite as a result of cellulose nanowhiskers' addition. Morphology and thermal tests were related to the properties of the films and confirmed that cellulose nanowhiskers were homogeneously dispersed into the matrix. Based on the results, this research demonstrated that the use of biodegradable polymer blend and cellulose nanowhiskers extracted from agro-waste represents an interesting alternative for the production of flexible biocomposite films for sustainable food packaging applications and for the development of eco-friendly technologies.
UV Barrier influence according to the amount of TiO2 in PBAT biodegradable flexible film
2020 - BARTOLOMEI, M.R.; ISHIKAWA, O.; BARTOLOMEI, S.S.; MOURA, E.M.
Manufacturing and consumption of polymeric products and packaging continues to grow despite concerns about environmental contamination due to improper post-consumer disposal, causing polymeric waste to emerge in increasingly remote places, polluting seas and soil, affecting flora, fauna and human health. Among these wastes are flexible food packaging. One of the alternatives to reduce this problem is the use of biodegradable materials, such as poly (butylene adipate-terephthalate) (PBAT), but the properties of this material do not meet all the needs of a food packaging, focus of this work. Additives and / or fillers must be added to improve the properties of this polymer, such as mechanical, thermal and barrier properties. One of the important features of a food packaging is the UV light barrier, as many products have shortened shelf life due to interaction with light. This work studies the effect of the addition of titanium dioxide (TiO2) particles to improve UV light barrier in biodegradable flexible PBAT films, with clay addition to improve mechanical properties. The films were obtained by melt processing so that the application is industrially and economically viable. For this, known amounts of TiO2 (0.1, 0.2 and 0.3 wt%) were added in a poly (vinyl alcohol) (PVA) solution, along with 0.5 wt% organophilized light green clay. This mixture was sonicated, poured onto PBAT pellets and oven dried. Then, the particle coated pellets were processed in a twin screw extruder, cooled and pelleted. Then the flexible film was produced in a flat die single screw extruder, thus producing 4 nanocomposites (PBAT + 0.5wt% Clay; PBAT + 0.5wt% Clay + 0.1wt% TiO2; PBAT + 0.5wt% Clay + 0.2wt% TiO2; PBAT + 0.5wt% Clay + 0.3wt% TiO2). The results of X Rays Diffraction (XRD), Scanning Electron Microscopy (SEM) and tensile test showed that the clay was exfoliated in the polymer matrix, allowing improvements in the mechanical strength and elongation of the films. UV-vis absorption assays showed that the higher the TiO2 concentration the higher the UV barrier.
Effect on flame propagation in recycled expanded polystyrene with flame retardant/white clay/titanium dioxide nanocomposite
2020 - BARTOLOMEI, S.S.; BARTOLOMEI, M.R.; MOURA, E.M.; WIEBECK, H.; OLIVEIRA, R.R.
Polystyrene is widely used in construction due to its properties such as low density, heat resistance, durability and ease of processing and molding. However, it is highly flammable, releases a lot of heat and toxic smoke when exposed to a flame. However, in order for a material to be applied in habitable indoor environments, it must comply with fire safety standards, which predict the behavior of materials during their burning. Halogenated flame retardants have been used to reduce the spread of flame, but they are toxic and polluting, so more environmentally friendly products are being developed. Polymeric nanocomposites, formed by inorganic nanoparticles, have many advantages in flame retardation, such as low heat release rate, low smoke and toxic gas production. Alternatively, the organofilized, exfoliated or polymer-intercalated montmorillonite clay (MMT) can be used to form a nanocomposite with greater flame resistance. However, for the clay to achieve the results required by the standards, it is necessary to add a large amount of particles, which generates agglomerates in the material and losses in the mechanical properties. Therefore, the use of clays to improve flame resistance to the material must be accompanied by the use of other flame retardants. Thus clay will provide reduction in flammability and secondary flame retardant will provide ignition resistance. The addition of other particles, together with clay, can corroborate with the reduction in flame spread of the material, with titanium dioxide being used to increase thermal stability, UV light stability, mechanical properties as well as reduction in flame spread. In this work expanded polystyrene (EPS) from construction waste, with flame retardant in its composition, was recycled and plasticized with glycerol. In this polymeric matrix was added white clay and titanium dioxide in order to maintain the flameproof properties and improve the mechanical and thermal properties of the material. The results showed that it is possible to recycle EPS and maintain flame self-extinguishing through the material even in the presence of glycerol as plasticizer. The addition of white clay improved the mechanical properties of the material and increased thermal stability, but impaired the fire behavior of the material, ceasing to self-extinguish the flame immediately after extinguishing the external flame. Titanium dioxide (TiO2) kept the mechanical and thermal properties unchanged and reduced flame propagation in the specimen when compared to the results of clay nanocomposite.