Pore Structure
Mostrando 1-12 de 412 artigos, teses e dissertações.
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1. Silicon carbide hollow fiber membranes developed for the textile industry wastewater treatment
Abstract In order to reduce the impacts of the industrial effluent on the environment, silicon carbide hollow fiber membranes were prepared by the precipitation-immersion technique and sintered at 1450 and 1500 °C. The membranes were characterized by X-ray diffraction, their surface structure was characterized by scanning electron microscopy and atomic forc
Cerâmica. Publicado em: 2021-06
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2. Optimization and Study of the Response Surface of Properties for the Synthesis of ZSM-5 Zeolites with Hierarchical Pore Structure Obtained by Desilication
Hierarchical ZSM-5 zeolites were prepared by alkali treatment (desilication) at two temperatures, two reaction times, and two NaOH concentrations. A 23 factorial design was used to study the effect of these variables on the crystallinity, microporosity, and mesoporosity of the zeolite due to the desilication treatment. The factorial design analysis showed th
J. Braz. Chem. Soc.. Publicado em: 2021-06
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3. Porosity of CHA Zeolite Driving the Formation of Polyaromatic Coke Species in the Methanol to Olefins Reaction
The pore size of the chabazite structure is exceptionally suitable for the methanol to olefins (MTO) reaction. The reaction has an induction period required for the formation of a hydrocarbon pool (HP), usually composed of aromatic compounds of different sizes. HP is alkylated by methanol and afterward cracked, leading to the formation of olefins. Despite th
J. Braz. Chem. Soc.. Publicado em: 2021-05
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4. Freeze-casting applied to ceramic materials: a short review of the influence of processing parameters
Abstract In recent years there is a high interest in the freeze-casting process because it is a simple, economical, and environmentally friendly method for obtaining highly porous materials. Most of the materials obtained by this technique have directional pore structure and anisotropic properties. However, a wide range of pore size and morphology can be obt
Cerâmica. Publicado em: 2021-03
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5. Reordering of Depolymerized Silicates as Adsorbents for Large Nitrogen Compounds
The adsorption capacities of two synthesized zeolites (crystalline ZSM-5 and semi-crystalline faujasite Y) for a mixture of indole, quinoline and carbazole were studied. The different samples obtained show different crystalline degree, mesoporosity and Si/Al ratios. The synthesis procedure is based on the simultaneous depolymerization of a mixture of high su
J. Braz. Chem. Soc.. Publicado em: 2021-01
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6. Constraints from magnetotellurics on the geological structure across a seismic area associated with water wells in the Paraná basin, Brazil
ABSTRACT: The occurrence of earthquakes associated with the opening of groundwater wells is a very rare phenomenon. We present the results from a magnetotelluric profile of about 4 km-long that crosses a seismic zone near the town of Bebedouro, in the Northeastern part of the intra-cratonic Paraná basin, in Brazil. The seismic activity is thought to be caus
Braz. J. Geol.. Publicado em: 13/01/2020
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7. Morphology, Crystalline Structure and Chemical Composition Of MAO Treated Ti-15Zr-Mo Surfaces Enriched with Bioactive Ions
In this study, MAO treatment was used to enrich, with bioactive Ca, Mg and P atoms, as-casted and heat-treated Ti-15Zr-xMo (x = 0, 5, 10 and 15 wt%) alloys, for potential use as advanced metallic biomaterials. The chemical composition of the surface was evaluated by EDS and XPS measurements. The morphology and microstructure was analyzed by OM and SEM images
Mat. Res.. Publicado em: 09/12/2019
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8. Development of Geopolymers for Catalyst Support Applications
A geopolymer with high specific surface area was synthesized from metakaolin, amorphous silica and KOH, in the absence of foaming or saponification agents. The mixture modelling technique was selected for this study among the Design of Experiments tools, using surface area and total pores volume as response variables. The Si/K = 2.46 and Si/Al = 1.37 ratios
Mat. Res.. Publicado em: 25/11/2019
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9. Mecanismos de queda do fluxo em membranas de microfiltração de poliéterimida aplicadas à clarificação de água produzida sintética
RESUMO Membranas de microfiltração de poliéterimida foram preparadas pelo método de inversão de fases para controlar a espessura, porosidade e tamanho de poros dos filmes. 1-metil-2-pirrolidona foi utilizada como solvente e água como não solvente. As propriedades das membranas foram avaliadas por meio de microscopia eletrônica de varredura, microfilt
Matéria (Rio J.). Publicado em: 25/11/2019
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10. Synthesis and characterization of mesoporous materials with SBA and MCM structure types
Resumo Materiais mesoporosos são estruturas promissoras para aplicação em catálise e adsorção devido à elevada área superficial e grande tamanho dos poros. Materiais mesoporosos foram sintetizados pelo método hidrotérmico com novos surfactantes, distintos daqueles observados na literatura, a fim de realizar um estudo de sua estrutura e obter materi
Cerâmica. Publicado em: 14/11/2019
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11. Development of Silica-Based Monoliths for the Capture of CO2
The synthesis of mesoporous materials in macroscopic scale, as for example, the monoliths, has been of great interest in view of the wide range of applications that this material holds. Thus, this work consists of the production of silica monoliths for the purpose of they being used in the carbon dioxide (CO2) adsorption process. The adsorbents were prepared
Mat. Res.. Publicado em: 30/09/2019
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12. X-ray Microtomography to Quantify Morphological Sandstones Properties
Abstract The sandstones of the Furnas Formation in the State of Paraná, south of Brazil, are located in regions with great importance due to the natural heritage found in the rocky forms and associated flora and fauna. This paper presents a detailed analysis of the internal structure of diverse sandstones of the Furnas Formation. X-ray microtomography allow
Braz. arch. biol. technol.. Publicado em: 12/08/2019