Barrier Properties
Mostrando 37-48 de 291 artigos, teses e dissertações.
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37. Polymeric Materials for Membrane Contactor Devices Applied to Water Treatment by Ozonation
AbstractIn water treatment process ozone is applied to disinfection and to remove organic pollutants. Membrane contactor devices are used as a physical barrier to separate two fluids without phase dispersion and it can be used to improve the ozonation efficiency. Polymeric materials are used in membrane contactors and they can react with ozone, suffering deg
Mat. Res.. Publicado em: 2015-10
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38. Three-dimensional reconstruction of compacted graphite in vermicular cast iron by manual serial sectioning
Microstructural characterization is an important tool to optimize the properties of engineering materials. Metallography is a common technique, but it provides two-dimensional images from (sometimes complex) three-dimensional microstructures. Three-dimensional reconstruction of microstructures provides more precise informa tion on the morphologies of the mat
Rem: Rev. Esc. Minas. Publicado em: 2015-09
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39. HYDROLYTIC DEGRADATION BEHAVIOR OF PLLA NANOCOMPOSITES REINFORCED WITH MODIFIED CELLULOSE NANOCRYSTALS
Bionanocomposites derived from poly(L-Lactide) (PLLA) were reinforced with chemically modified cellulose nanocrystals (m-CNCs). The effects of these modified cellulose nanoparticles on the mechanical and hydrolytic degradation behavior of polylactide were studied. The m-CNCs were prepared by a method in which hydrolysis of cellulose chains is performed simul
Quím. Nova. Publicado em: 2015-09
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40. Sorbitol-Plasticized and Neutralized Chitosan Membranes as Skin Substitutes
Chitosan is soluble in diluted acid solutions and can easily form films by casting. However, residual acid neutralization should be performed for biomedical applications what may compromise physical and mechanical properties of the films. Thus, plasticizers can be added to improve these properties. The aim of this study was to characterize morphological, bar
Mat. Res.. Publicado em: 2015-08
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41. Using glycerol produced from biodiesel as a plasticiser in extruded biodegradable films
AbstractThe demand for renewably sourced biodegradable materials has increased the need to produce materials that combine appropriate functional properties at competitive costs. Thermoplastic starch and polyester blends are an interesting alternative to current materials due to the low cost of starch and the functional properties and processability of the re
Polímeros. Publicado em: 2015-08
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42. CARACTERIZAÇÃO DE NANOFIOS DE GERMÂNIO SINTETIZADOS UTILIZANDO COBRE COMO CATALISADOR
This paper presents reliable synthesis of germanium nanowires by the vapor-liquid-solid method using copper as an alternative catalyst to gold, the most commonly used metal. The morphological study showed long range single-crystalline germanium nanowires with diamond structure and diameters ranging from 20 nm to 80 nm and lengths in tenths of a micrometer
Quím. Nova. Publicado em: 2015-07
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43. UNA PROPUESTA PARA ENSEÑAR EL EFECTO DE LA FORMA DE LAS MOLÉCULAS EN LA REACTIVIDAD QUÍMICA
We address the concept of steric effect in the pursuit of establishing quantitative correlations between reactivity of molecules and their molecular shape. To this end, a set of series of SN2 reactions were modeled to compute the energy barrier height and the molecular volume, atomic charges and dipole moment of molecules. We introduced the Kappa index to ch
Quím. Nova. Publicado em: 2015-03
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44. New Sol-gel Formulations to Increase the Barrier Effect of a Protective Coating Against the Corrosion and Wear of Galvanized Steel
This study proposes a new pretreatment method that uses alkoxide precursors with a plasticizing agent; the purpose of this study is to improve the electrochemical and mechanical properties of a galvanized steel surface. Galvanized steel was covered with a hybrid film obtained from a sol that consisted of two alkoxide precursors, 3 - (trimethoxysilylpropyl) m
Mat. Res.. Publicado em: 2015-02
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45. Characterization of Siloxane-poly(methyl methacrylate) Hybrid Films Obtained on a Tinplate Substrate Modified by the Addition of Organic and Inorganic Acids
Tinplate is used to food packaging and other types of packages. The corrosion resistance of the tinplate has been study due the necessity of an alternative to high environmental impact of chromatization process. Therefore protective coatings as hybrid films base elaborations with different acids are studied to improve the barrier effect against corrosion. Th
Mat. Res.. Publicado em: 2015-02
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46. BIOFILMS BASED ON CANIHUA FLOUR (Chenopodium Pallidicaule): DESIGN AND CHARACTERIZATION
This work aims to (1) produce and characterize the flour obtained from two varieties of canihua, cupi and illpa-inia, and (2) evaluate the ability of these flours to form biofilms. The flours produced contain proteins, starches, lipids, organic substances containing phenol groups, and high percentages of unsaturated fatty acids. Films produced from the illpa
Quím. Nova. Publicado em: 2015-01
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47. Mechanical, thermal, and barrier properties of methylcellulose/cellulose nanocrystals nanocomposites
In this work, the effects of incorporating cellulose nanocrystals from soy hulls (WSH30) on the mechanical, thermal, and barrier properties of methylcellulose (MC) nanocomposites were evaluated. MC/WSH30 nanocomposite films with different filler levels (2, 4, 6, 8, and 10%) were prepared by casting. Compared to neat MC film, improvements in the mechanical an
Polímeros. Publicado em: 2014-12
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48. Corrosion resistance of 2024 aluminum alloy coated with plasma deposited a-C:H:Si:O films
AA 2024 aluminum alloy is widely employed in aeronautic and automobilist industries. Its hardness and low density are attractive properties for such industrial areas. However, since it contains copper, it undergoes severe corrosion in aggressive media as saline or low Earth orbit environments. In this work, it was investigated the properties of films deposit
Mat. Res.. Publicado em: 2014-12