Stability Of Membranes
Mostrando 13-24 de 205 artigos, teses e dissertações.
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13. Synthesis of the Perovskite-Type BaCe0.8Pr0.05Cu0.15O3-δ via EDTA-Citrate
BaCeO3-based ceramics are ionic and electronic conductors that can be applied to oxygen sensors, solid oxide fuel cells and oxygen permeable membranes. However, the low chemical stability at high temperatures of these materials motivates studies involving doping of A and/or B sites of the perovskite structure. In this context, the present work aimed to synth
Mat. Res.. Publicado em: 06/11/2017
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14. IN SITU PREPARED TiO2 NANOPARTICLES CROSS-LINKED SULFONATED PVA MEMBRANES WITH HIGH PROTON CONDUCTIVITY FOR DMFC
Organic/inorganic membranes based on sulfonated poly(vinyl alcohol) (SPVA) and in situ prepared TiO2 nanoparticles nanocomposite membranes with various compositions were prepared to use as proton exchange membranes in direct membrane fuel cells. Poly(vinyl alcohol) (PVA) was sulfonated and cross-linked separately by 4-formylbenzene-1,3-disulfonic acid disodi
Quím. Nova. Publicado em: 2016-07
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15. Poly(vinyl alcohol)-hyaluronic Acid Membranes for Wound Dressing Applications: Synthesis and
in vitro Bio-EvaluationsPhysically crosslinked poly(vinyl alcohol)-hyaluronic acid (PVA-HA) hydrogel membranes composed of different amounts of HA were prepared by freeze-thawing (F-T) method. F-T cycle was repeated for three consecutive cycles. HA was chosen and routinely utilized in the local treatment of chronic wounds, because of its advantages as, HA is endogenous and biode
J. Braz. Chem. Soc.. Publicado em: 2015-07
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16. Immobilization of myoglobin in sodium alginate composite membranes
Abstract The immobilization of myoglobin in sodium alginate films was investigated with the aim of evaluating the protein stability in an ionic polymeric matrix. Myoglobin was chosen due to the resemblance to each hemoglobin tetramer. Sodium alginate, being a natural polysaccharide, was selected as the polymeric matrix because of its chemica
Polímeros. Publicado em: 2015-06
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17. Myoglobin entrapment in poly(vinyl alcohol) dense membranes
Our goal in this study was the immobilization of myoglobin in poly(vinyl alcohol) dense membranes. Glutaraldehyde was investigated both as the crosslinking agent, aiming to increase the membrane stability in aqueous medium, and as the vehicle to bind myoglobin and PVA. Reaction and membrane synthesis were carried simultaneously in mild operating conditions i
Braz. J. Chem. Eng.. Publicado em: 2014-09
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18. Metal nanoparticles/ionic liquid/cellulose: polymeric membrane for hydrogenation reactions
Rhodium and platinum nanoparticles were supported in polymeric membranes with 10, 20 and 40 µm thickness. The polymeric membranes were prepared combining cellulose acetate and the ionic liquid (IL) 1-n-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide (BMI.(NTf)2. The presence of metal nanoparticles induced an increase in the polymeric membrane
Polímeros. Publicado em: 18/04/2014
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19. Synthesis and characterization of sulfonated poly(ether imide) with higher thermal stability and effect on CO2, N2, and O2 permeabilities
An experimental design in different reaction conditions was applied to modify poly(ether imide), PEI, by sulfonation using acetyl sulfate. Higher temperatures and reaction times led to higher ion exchange capacity. The thermal analysis showed that our sulfonation approach accomplished preparing sulfonated PEI maintaining the thermal stability of its parent m
Mat. Res.. Publicado em: 18/02/2014
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20. Synovial Sarcoma in Head and Neck: A Case Report
Introduction Synovial sarcoma is a malignant tumor of mesenchymal pluripotent cells. Objectives We present a case of synovial sarcoma in the posterolateral wall of the oropharynx. Resumed report The patient, a 23-year-old woman, was admitted with a history of dysphagia and difficulty in breathing for 8 months, resulting in progressive deteriora
Int. Arch. Otorhinolaryngol.. Publicado em: 2014-01
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21. Organic-inorganic hybrid membranes in separation processes: a 10-year review
In relation to some inorganic membranes, polymeric membranes have relatively low separation performance. However, the processing flexibility and low cost of polymers still make them highly attractive for many industrial separation applications. Polymer-inorganic hybrid membranes constitute an emerging research field and have been recently developed to improv
Braz. J. Chem. Eng.. Publicado em: 2013-12
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22. Preparation, characterization and gas permeation study of PSf/MgO nanocomposite membrane
Nanocomposite membranes composed of polymer and inorganic nanoparticles are a novel method to enhance gas separation performance. In this study, membranes were fabricated from polysulfone (PSf) containing magnesium oxide (MgO) nanoparticles and gas permeation properties of the resulting membranes were investigated. Membranes were prepared by solution blendin
Braz. J. Chem. Eng.. Publicado em: 2013-09
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23. Castor oil and commercial thermoplastic polyurethane membranes modified with polyaniline: a comparative study
The study of conducting polymeric membranes is decisive in some areas, as in fuel cells and electrodialysis. This work aims the study of membranes using conventional and conductive polymers blends. Two types of polyurethane were used as conventional polymers, commercial thermoplastic polyurethane and polyurethane synthesized from castor oil and 4-4-dicyclohe
Mat. Res.. Publicado em: 10/05/2013
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24. Stability of a nanofiltration membrane after contact with a low-level liquid radioactive waste
This study investigated the treatment of a liquid radioactive waste containing uranium (235U + 238U) using nanofiltration membranes. The membranes were immersed in the waste for 24-5000 h, and their transport properties were evaluated before and after the immersion. Surface of the membranes changed after immersion in the waste. The SW5000 h specimen lost its
Quím. Nova. Publicado em: 2013