99 resultados para nanocompósitos


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In order to improve the quality and safety of food, the active packaging emerges as a new technology based on the release of composites beneficial to food products. Thus, biodegradable films incorporated with active substances have the function of acting as a barrier to external elements, protecting the product and increasing its shelf life. They are formulated from proteins, polysaccharides, lipids or from the combination of these compounds. However, there is a need to improve the performance properties of these packages. Nanotechnologies, then, emerges with the study of many nanoparticles as additives to modify the performance of biodegradable polymers. With this, we aimed at developing and active antioxidant film of corn starch blenders and whey protein isolate with rosemary essential oil or microcapsules of rosemary essential oil reinforced with sodium montmorillonite (MMTNa + ) nanoparticles by extrusion. The films were developed and characterized in a first stage for the selection of the best polymeric blender using the following analyses: water vapor permeability (WVP), machanical properties; optical, thermogravimetry (TG), differential scanning calorimetry (DSC), x-ray diffraction (XRD) and scanning electron microscopy (SEM). In the second stage, montmorillonite clay nanoparticles and rosemary essential oil were added as reinforcement to evaluate its antioxidant effect. In a third stage, we studied the addition of microcapsules of rosemary essential oil (MR) as a form of protecting the active agent and its antioxidant potential in the films. The results indicate that the development of p olymeric blender with 30% of corn starch substitution is the most indicated for future work. The addition of rosemary essential oil or microcapsule of rosemary essential oil allowed for the obtaining of nanocomposites with antioxidant potential for application in food packages.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Descrito como o presente Privilégio de Invenção, refere-se a um processo sobre novos materiais nanocompósitos de polímeros híbridos, preparados com sucesso baseados em um novo procedimento para cura de resinas epóxi comerciais ou não comerciais (tais como resinas epóxi híbridas orgânica-inorgânica, e outras que contenham grupos epóxi), sendo que, para tanto, é usado um silsesquioxano, substituído com éster, sendo genericamente definido como éster-silsesquioxano e etilenodiamina, como agentes de cura, sendo que o processo para cura destes materiais possa ser realizado a frio e que a cura se encerre em um tempo menor ou igual a duas horas.

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The patent application relates to the method for producing functional nanocomposites made of paramagnetic nanoparticles with Ni0.5Zn0.5Fe2O4 stoichiometry and to the thus obtained product. The method comprises at least the following steps: producing functional nanocomposites by the modified polyol method; mechanically blending the functional nanocomposites with natural rubber and adding vulcanising agents; and thermoforming the functional nanocomposite.

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Pós-graduação em Engenharia Mecânica - FEIS

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Pós-graduação em Química - IQ

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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This work shows the preparation and characterization of the new nanocomposites based on fibroin and biocellulose. Bacterial cellulose (BC) is an exopolysaccharide produced by bacteria of the genus Gluconacetobacter, which it has identical chemical structure of the cellulose from plants and it has gained attention in the field of research for its unique properties as excellent mechanical properties when dry and hydrated , higher capacity of water retention, moldability , biodegradability and excellent biological affinity . Silk fibroin (SF) is a structural protein present in the cocoon of the silkworm, Bombyx mori, has been identified as suitable for developing optical devices, tissue engineering application, enzyme immobilization, controlled release drug agent biopolymer. Silk fibroin/bacterial cellulose nanocomposite films were prepared impregnating different cellulose charges (0.5 %, 1.0 %, 1.5 %, 2.5 %, 5.0 % and 10.0 %) weight/weight. According mechanical tests and water and Paynes's cup permeability showed that SF/BC 1% nanocomposite has the most relevant results. Poliethylenoglicol (PEG) containing SF films improved optical and mechanical properties when compared to pristine SF film. New SF/BC nanocomposites could be applied in Medicine, as biodegradable packaging and flexible substrates for OLEDs.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A presente invenção refere-se ao desenvolvimento de um nanocompósito de biocelulose e dietilditiocarbamato (CB-DETC) que é formado por uma matriz polimérica de celulose bacteriana com nanofibras revestidas com derivados de dietilditiocarbamato no preparo de um biocurativo para o controle de Leishmaniose Tegumentar. As principais propriedades observadas nesse biocompósito são a sua flexibilidade, fácil aplicação em lesões cutâneas, capacidade leishmanicida, ausência de toxicidade e liberação sustentada do composto ativo, reduzindo a necessidade de troca do curativo.